Arihant Science Class 10 Term 1 Sample Paper

44 CBSE Sample Paper Science Class X (Term I) 15. Identify the phase of circulation which is represented in the diagram of heart given below. Arrows indicate contraction of the chambers shown. (a) Blood transferred to the right ventricle and left ventricle simultaneously (b) Blood is transferred to lungs for oxygenation and is pumped into various organs simultaneously (c) Blood transferred to the right auricle and left auricle simultaneously (d) Blood is received from lungs after oxygenation and is received from various organs of the body 16. Observe the diagram of human digestive system. A B C D Latest CBSE SAMPLE PAPER Match the labelling referred in Column I and correlate with the function in Column II. Column I 1. Column II A The length of this depends on food the organism eats. Initial phase of starch digestion B 2. Increases the efficiency of lipase enzyme action. This is the site of the complete digestion of carbohydrates, proteins and fats. C 3. D 4. Codes AB C D (a) 1 2 3 4 (b) 2 3 4 1 (c) 2 4 3 1 (d) 4 1 2 3

CBSE Sample Paper Science Class X (Term I) 45 17. Which of the following mirror is used by a dentist to examine a small cavity in a patient’s teeth? (a) Convex mirror (b) Plane mirror (c) Concave mirror (d) Any spherical mirror 18. Which diagram shows image formation of an object on a screen by a converging lens? 2 × Focal length 2 × Focal length (a) (b) Object Object Screen Screen Focal length Focal length (d) (c) Object Object Screen Screen 19. Which of the following can make a parallel beam of light when light from a point source is incident on it? (a) Concave mirror as well as convex lens (b) Convex mirror as well as concave lens (c) Two plane mirrors placed at 90° to each other (d) Concave mirror as well as concave lens 20. Consider these indices of refraction: glass: 1.52; air: 1.0003; water: 1.333. Based on the Latest CBSE SAMPLE PAPER refractive indices of three materials, arrange the speed of light through them in decreasing order. (a) The speed of light in water > the speed of light in air > the speed of light in glass (b) The speed of light in glass > the speed of light in water > the speed of light in air (c) The speed of light in air > the speed of light in water > the speed of light in glass (d) The speed of light in glass > the speed of light in air > the speed of light in water 21. If a beam of red light and a beam of violet light are incident at the same angle on the inclined surface of a prism from air medium and produce angles of refraction r and v respectively, which of the following is correct? (a) r = v (b) r > v (c) r = 1 (d) r < v v 22. Concave mirror CF P

46 CBSE Sample Paper Science Class X (Term I) Examine the above figure and state which of the following option is correct? [one small box in the figure is equal to 1 cm] (a) The mirror has a focal length of - 6 cm and will produce an image of magnification + 1. (b) The mirror has a focal length of - 3 cm and will produce an image of magnification - 1. (c) The mirror has a focal length of - 3 cm and will produce an image of magnification + 1. (d) The mirror has a focal length of - 6 cm and will produce an image of magnification - 1. 23. Q Air P Glass Air O The angle of incidence from air to glass at the point O on the hemispherical glass slab is (a) 45° (b) 0° (c) 90° (d) 180° 24. A prism ABC (with BC as base) is placed in different orientations. A narrow beam of white light is incident on the prism as shown in below figure. In which of the following diagrams, after dispersion, the third colour from the top of the spectrum corresponds to the colour of the sky? AC B CC AA B CA (iii) B B (i) (ii) (iv) (a) (i) (b) (ii) (c) (iii) (d) (iv) Section B Section B consists of 24 questions (Sl. No. 25 to 48). Attempt any 20 questions from this section. The first attempted 20 questions would be evaluated. 25. Heated Limestone Step 1 X + CO2 Latest CBSE SAMPLE PAPER + H2O Step 2 Slaked lime Identify the correct option from the given table which represents the type of reactions occurring in step 1 and step 2. Endothermic Exothermic (a) O P (b) P O (c) P P (d) O O

CBSE Sample Paper Science Class X (Term I) 47 26. In which year is the concentration of hydrogen ion the highest? pH value 6.00 5.00 4.00 3.00 2.00 1.00 0.00 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Rain pH value (a) 2002 (b) 2008 (c) 2011 (d) 2005 27. The diagram shows the reaction between metal and dil. acid. Mg+ dil.HCl Zn+ B Cu+ Ca+ dil.HCl dil.HCl dil.HCl A C D What is the reason for different behaviour of Mg in test tube B ? (a) Mg is lighter element than dil. HCl (b) Mg reacts with dil. HCl to produce H gas which helps in floating 2 (c) Mg reacts with dil. HCl to produce N gas which helps in floating 2 (d) Mg reacts with dil. HCl to produce CO gas which helps in floating 2 28. The table shown below gives information about four substances: A, B, C and D. Substance Electrical conductivity Melting point (K) Solid Liquid/Aqueous A 295 Good Good B 1210 Poor Good C 1890 Poor Good D 1160 Poor Poor Identify ionic compounds from the above given substances. Latest CBSE SAMPLE PAPER (a) A, B (b) B, C (c) A, B, D (d) A, C, D 29. Vinay observed that the stain of curry on a white shirt becomes reddish-brown when soap is scrubbed on it, but it turns yellow again when the shirt is washed with plenty of water. What might be the reason for his observation? I. Soap is acidic in nature. II. Soap is basic in nature. III. Turmeric is a natural indicator which gives reddish tinge in bases. IV. Turmeric is a natural indicator which gives reddish tinge in acids. (a) I and II (b) II and III (c) I and IV (d) II and IV

48 CBSE Sample Paper Science Class X (Term I) 30. In which of the following setups would the bulb glow? 6 volt battery Bulb 6 volt battery Bulb Switch Switch I. Beaker II. Beaker 6 volt battery 6 volt battery Nail Nail Dilute HCl solution Sugar solution Rubber cork Rubber cork Bulb Bulb Switch Switch Beaker Beaker III. IV. Nail Nail Alcohol in water Lime water Rubber cork Rubber cork (a) I and II (b) I and IV (c) II, III and IV (d) I, II and IV Direction (Q. No. 31 to 34) Consist of two statements – Assertion and Reason. Answer these questions selecting the appropriate option given below : (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true, but R is not the correct explanation of A. (c) A is true, but R is false. (d) A is false, but R is true. 31. Assertion Fresh milk in which baking soda is added, takes a longer time to set as curd. Reason Baking soda decreases the pH value of fresh milk to below 6. Latest CBSE SAMPLE PAPER 32. Assertion Decomposition of vegetable matter into compost is an endothermic reaction. Reason Decomposition reaction involves breakdown of a single reactant into simpler products. 33. Assertion Resins and gums are stored in old xylem tissue in plants. Reason Resins and gums facilitate transport of water molecules. 34. Assertion Sky appears blue in the day time. Reason White light is composed of seven colours.

CBSE Sample Paper Science Class X (Term I) 49 35. The table given below shows the reaction of a few elements with acids and bases to evolve hydrogen gas. Which of these elements form amphoteric oxides ? Element Acid Base A OO B PP C PO D PP (a) A and D (b) Band D (c) A and C (d) B and C 36. In which of the following groups of organisms, blood flows through the heart only once during one cycle of passage through the body? (a) Rabbit, parrot, turtle (b) Frog, crocodile, pigeon (c) Whale, Labeo, penguin (d) Shark, dog fish, sting ray 37. What is common between extensive network of blood vessels around walls of alveoli and in glomerulus of nephron? (a) Thick walled arteries richly supplied with blood (b) Thin walled veins poorly supplied with blood (c) Thick walled capillaries poorly supplied with blood (d) Thin walled capillaries richly supplied with blood 38. Plants use completely different process for excretion as compared to animals. Which one of the following processes is not followed by plants for excretion? (a) They can get rid of excess water by transpiration (b) They selectively filter toxic substances through their leaves (c) Waste products are stored as resins and gums in old xylem (d) They excrete waste substances into the soil around them 39. If the power of a lens is - 4.0 D, then it means that the lens is a Latest CBSE SAMPLE PAPER (a) concave lens of focal length - 50 m (b) convex lens of focal length + 50 cm (c) concave lens of focal length - 25 cm (d) convex lens of focal length - 25 m 40. Rays from Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size of its image is equal to the size of the object? (a) 30 cm in front of the mirror (b) 15 cm in front of the mirror (c) Between 15 cm and 30 cm in front of the mirror (d) More than 30 cm in front of the mirror 41. In which of the following groups of organisms, food material is broken down outside the body and then absorbed in? (a) Mushroom, green plants, Amoeba (b) Yeast, mushroom, bread mould (c) Paramecium, Amoeba, Cuscuta (d) Cuscuta, lice, tapeworm

50 CBSE Sample Paper Science Class X (Term I) 42. In a person, the tubule part of the nephron is not functioning at all. What will be its effect on urine formation? (a) The urine will not be formed (b) Quality and quantity of urine is unaffected (c) Urine is more concentrated (d) Urine is more diluted 43. If the real image of a candle flame formed by a lens is three times the size of the flame and the distance between lens and image is 80 cm, at what distance should the candle be placed from the lens? (a) - 80 cm (b) - 40 cm (c) - 40 cm (d) - 80 cm 3 3 44. Principal axis F C Object While looking at the above diagram, Nalini concluded the following ? I. The image of the object will be a virtual one. II. The reflected ray will travel along the same path as the incident ray but in opposite direction. III. The image of the object will be inverted. IV. This is a concave mirror and hence the focal length will be negative. Which of the above statements are correct? (a) I and II (b) I and III (c) II, III and IV (d) I, II, III and IV 45. Medium 1 1 Medium 2 2 Latest CBSE SAMPLE PAPER Medium 3 34 Medium 4 4 In the above diagram light is travelling through different media. It is noted by a scientist that Ð1 = Ð 3 = Ð4 but Ð2 < Ð1. Which of the following statement would be correct? (a) Medium 1 is denser than medium 3 but it’s density is equal to medium 2 (b) Medium 2 is the rarest medium (c) Medium 3 is denser than medium 1 (d) Medium 1 and 3 are essentially the same medium, but medium 2 is denser than 1 and 3 46. The refractive index of flint glass is 1.65 and that for alcohol is 1.36 with respect to air. What is the refractive index of the flint glass with respect to alcohol ? (a) 0.82 (b) 1.21 (c) 1.11 (d) 1.01

CBSE Sample Paper Science Class X (Term I) 51 47. A¢ A F2 B¢ F1 B O The above lens has a focal length of 10 cm. The object of height 2 mm is placed at a distance of 5 cm from the pole. Find the height of the image. (a) 4 cm (b) 6.67 mm (c) 4 mm (d) 3.33 mm 48. A cable manufacturing unit tested few elements on the basis of their physical properties. Properties W XY Z Malleable Yes No No Yes Ductile Yes No No Yes Electrical conductivity Yes Yes Yes No Melting Point High Low Low High Which of the above elements were discarded for usage by the company? (a) W, X, Y (b) X, Y, Z (c) W, X, Z (d) W, X, Z Section C This Section C consists of three Cases followed by questions. There are a total of 12 questions in this Latest CBSE SAMPLE PAPER section. Attempt any 10 questions from this section. The first attempted 10 questions would be evaluated. Case I The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds. One such compound is sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers. The table shows the mass of various compounds obtained when 1 litre of sea water is evaporated. Compound Formula Mass of solid present/g Sodium chloride NaCl 28.0 Magnesium chloride MgCl2 8.0 Magnesium sulphate MgSO 4 6.0 Calcium sulphate CaSO 4 2.0 Calcium carbonate CaCO 3 1.0 Total amount of salt obtained 45.0 49. Which compound in the table reacts with acids to release carbon dioxide ? (a) NaCl (b) CaSO4 (c) CaCO3 (d) MgSO4

52 CBSE Sample Paper Science Class X (Term I) 50. How many grams of magnesium sulphate are present in 135 g of solid left by evaporation of sea water? (a) 6 g (b) 12 g (c) 18 g (d) 24 g 51. What is the saturated solution of sodium chloride called? (a) Brine (b) Lime water (c) Slaked lime (d) Soda water 52. What is the pH of the acid which is used in the formation of common salt? (a) Between 1 to 3 (b) Between 6 to 8 (c) Between 8 to 10 (d) Between 11 to 13 Case II The Figure shown alongside represents an activity to prove the requirements for photosynthesis. During this activity, two healthy potted plants were kept in the dark for 72 hours. After 72 hours, KOH is kept in the watch glass in setup X and not in setup Y. Both these setups are air tight and have been kept in light for 6 hours. Then, iodine test is performed with one leaf from each of the two plants X and Y. Bell jar Watch-glass containing potassium hydroxide X Y 53. This experimental setup is used to prove essentiality of which of the following requirements of photosynthesis? (a) Chlorophyll (b) Oxygen (c) Carbon dioxide (d) Sunlight 54. The function of KOH is to absorb (a) oxygen (b) carbon dioxide (c) moisture (d) sunlight Latest CBSE SAMPLE PAPER 55. Which of the following statements shows the correct results of Iodine Test performed on the leaf from plant X and Y respectively? (a) Blue - black colour would be obtained on the leaf of plant X and no change in colour on leaf of plant Y (b) Blue - black colour would be obtained on the leaf of plant Y and no change in colour on leaf of plant X (c) Red colour would be obtained on the leaf of plant X and brown colour on the leaf of plant Y (d) Red colour would be obtained on the leaf of plant Y and brown colour on the leaf of plant X 56. Which of the following steps can be followed for making the apparatus air tight? I. Placing the plants on glass plate. II. Using a suction pump. III. Applying vaseline to seal the bottom of jar. IV. Creating vacuum. (a) I and II (b) II and III (c) I and III (d) II and IV

CBSE Sample Paper Science Class X (Term I) 53 Case III. Noor, a young student, was trying to demonstrate some properties of light in her Science project work. She kept ‘X’ inside the box (as shown in the figure) and with the help of a laser pointer made light rays pass through the holes on one side of the box. She had a small butter-paper screen to see the spots of light being cast as they emerged. Ray 2 Ray 1 X Ray 2 Ray 1 57. What could be the ‘X ’ that she placed inside the box to make the rays behave as shown? (a) a converging lens (b) a parallel-sided glass block (c) a plane mirror (d) a triangular prism 58. She measured the angles of incidence for both the rays on the left side of the box to be 48.6°. She knew the refractive index of the material ‘X ’ inside the box was 1.5. What will be the approximate value of angle of refraction? (a) 45° (b) 40° (c) 30° (d) 60° (Use the value : sin 48.6° » 0.75) 59. Her friend noted the following observations from this demonstration : (i) Glass is optically rarer than air. (ii) Air and glass allow light to pass through them with the same velocity. (iii) Air is optically rarer than glass. (iv) Speed of light through a denser medium is faster than that of a rarer medium. (v) The ratio of sine of angle of incidence in the first medium to the ratio of sine of angle of refraction in the second medium, gives the refractive index of the second medium with respect to the first one. Which one of the combination of the above statements given below is correct? (a) (ii), (iv) and (v) are correct (b) (iii) and (iv) are correct (c) (i), (iv) and (v) are correct (d) (iii) and (v) are correct 60. If the object inside the box was made of a material with a refractive index less than 1.5 Latest CBSE SAMPLE PAPER then (a) lateral shift of the rays would have been less (b) lateral shift of the rays would have been more (c) lateral shift of the rays would remain the same as before (d) there is not enough information to comment on any of the above statements ANSWERS 1. (b) 2. (b) 3. (d) 4. (b) 5. (d) 6. (a) 7. (c) 8. (b) 9. (a) 10. (c) 11. (c) 12. (b) 13. (d) 14. (d) 15. (b) 16. (b) 17. (c) 18. (c) 19. (a) 20. (c) 21. (d) 22. (b) 23. (b) 24. (b) 25. (c) 26. (a) 27. (b) 28. (b) 29. (b) 30. (b) 31. (c) 32. (d) 33. (c) 34. (b) 35. (b) 36. (d) 37. (d) 38. (b) 39. (c) 40. (a) 41. (b) 42. (d) 43. (d) 44. (c) 45. (d) 46. (b) 47. (c) 48. (b) 49. (c) 50. (c) 51. (d) 52. (a) 53. (c) 54. (b) 55. (b) 56. (c) 57. (b) 58. (c) 59. (d) 60. (a)

54 CBSE Sample Paper Science Class X (Term I) SOLUTIONS 1. When Reema added approximately 4 mL of atoms for each element in the reaction is same or equal for both the reactants and the products. potassium iodide solution to 5 mL of lead In (a) reaction, nitrate solution, then yellow precipitate of lead Fe(s) + 4H2O(g) ¾® Fe3O4(s) + 4H2(g) iodide was formed along with potassium Fe-atoms are not balanced. nitrate. In (b) reaction, 3Fe(s) + 4H2O(g) ¾® Fe3O4(s) + 4H2(g) 2KI + Pb(NO ) ¾® PbI + 2KNO 32 2 3 Number of atoms of all elements are equal on both the side of the reaction. Hence, it is a Potassium Lead nitrate Lead iodide Potassium balanced equation. iodide (Yellow ppt.) nitrate In (c) reaction, 3Fe(s) + H2O(g) ¾® Fe3O4(s) + 4H2(g) 2. In the given experiment, the gas evolved (A) is O-atoms are unbalanced. hydrogen as zinc reacts with dil. H2SO4 to form zinc chloride and hydrogen gas. In (d) reaction, 3Fe(s) + 4H2O(g) ¾® Fe3O4(s) + 4H2(g) Zn + dil.HCl ¾® ZnCl + H­ 2 2 H-atoms are not balanced. (Zinc) (Dilute (Zinc (Hydrogen) hydrochloric acid) chloride) The presence of hydrogen is tested by bringing 5. Acid and base reacts with each other to form a burning candle near the soap bubbles filled salt and water, this reaction is known as with gas A (hydrogen). On doing so, hydrogen neutralisation reaction. gas burns with pop sound due to the reaction Acid + Base ¾® Salt + H2O between hydrogen and oxygen present in the As the pH of acid is below 7, so the letter air makes a small explosion with pop sound. which donates the area of the graph where both acid and salt are present after addition of 3. (i) When copper metal reacts with dilute excess acid to an alkali is (D). hydrochloric acid, then no reaction occurs 6. The reaction between iron and copper sulphate solution is as follows : because copper cannot displace hydrogen CuSO4 + Fe ¾® Cu + FeSO4 from HCl to evolve H2 gas as it is less The substance which gets oxidised is called reactive than hydrogen. reducing agent. Hence, in the given reaction, Fe is oxidised and consequently acts as Latest CBSE SAMPLE PAPER (ii) When iron reacts with dilute hydrochloric reducing agent by gaining oxygen atoms to acid, then iron chloride and hydrogen gas form FeSO4. is formed. Fe(s)+ dil. HCl(aq) ¾® FeCl2(aq)+ H2(g) 7. The chemical reaction between copper and oxygen can be written as : In this reaction, Fe being more reactive, Cu(s) + O2(g) ¾® 2 CuO(s) displaces hydrogen from hydrochloric acid to form FeCl2 and H2 gas. In this reaction, two reactants, Cu and O2 react with each other and form single product, (iii) The reaction between magnesium and i.e. copper oxide, CuO. Hence, this reaction is dilute hydrochloric acid produces categorised as combination reaction. magnesium chloride and hydrogen gas. 8. The term ‘parent acid’ and ‘parent base’ are Mg(s)+ dil. HCl(aq)¾® MgCl2(aq) + H2(g) used to describe the original compounds that combined to make the salt. In this reaction, Mg being more reactive, displaces hydrogen from hydrochloric acid So, calcium carbonate salt can be obtained by to form MgCl2 and H2 gas. the reaction between H2CO3 (parent acid) and (iv) When zinc is treated with dilute HCl, then Ca(OH)2 (parent base) to form calcium zinc chloride and hydrogen gas is carbonate salt and water. produced. Zn(s) + dil. HCl(aq) ¾® ZnCl2(aq)+ H2(g) In this reaction, zinc being more reactive, displaces hydrogen from HCl and forms zinc chloride and hydrogen gas. Hence, the combination of (ii) and (iv) is correct. 4. A balanced equation is an equation for a H2CO3 + Ca(OH)2 ¾® CaCO3 + H2O chemical reaction in which the number of Carbonic acid Calcium hydroxide Calcium Water (Parent acid) (Parent base) carbonate (Salt)

CBSE Sample Paper Science Class X (Term I) 55 9. The process of diluting a concentrated acid is a 16. Option (b) shows correct matches. highly exothermic one. Thus, while diluting a concentrated acid, one should add acid to (A) Intial phase of starch digestion take place water with constant stirring to avoid any in mouth by the help of salivary glands. mishappening. The heat generation in the process may cause the mixture to splash out. (B) Liver increases the efficiency of lipase enzyme by providing alkaline medium in 10. The balancing of chemical equation is based on small intestine. the law of conservation of mass, which states that the total mass of the system must remain (C) Small intestine is the site of the complete constant throughout the reaction i.e. mass of digestion of carbohydrates, proteins and fats. the reactants should be equal to total mass of the product. (D) The length of small intestine depends on food the organism eats. 11. Option (c) is the correct. 17. Concave mirrors are used by dentists to examine (iii)-Alveoli are thin walled sac-like structures a small cavity in a patient’s teeth because these present in lungs for gaseous exchange. mirrors give enlarged image of the teeth. (i)-Trachea is supported by ring of cartilages If an object is placed close to a concave mirror, it which prevent it from collapsing in the forms an erect and enlarged image of the object. absence of air. So, the dentist holds the mirror in such a way that the tooth lies within its focus as shown below. (ii)-Ribs lift up, when we breathe in. A¢ (iv)-Diaphragm contracts and flattens, when we breathe in. A 12. (i) Salivary glands present in our mouth C FB P B¢ secrete salivary amylase for digestion of starch. 18. The ray coming parallel to the principal axis after refraction will pass through principal (ii) Stomach secretes pepsin which helps in focus in case of convex lens. digestion of protein. Similarly, a ray directed to optical centre will (iii) Trypsin is produced by the pancreas in an emerge out undeviated. inactive form called trypsinogen. It enters the small intestine and is converted to Therefore, the correct image formation of an active trypsin. object on a screen by a converging lens is, 13. The opening and closing of stomata is Focal length controlled by the guard cells. When water flows into the guard cells, they swell up and Object Latest CBSE SAMPLE PAPER the curved surface causes the stomata to open. When the guard cells loses water, they shrink Screen and become flacid, thus closing the stomata. 19. Concave mirror as well as convex lens can make 14. (iv) Vena cava collects deoxygenated blood a parallel beam of light when light from a point from body parts and carries it to right source is incident on it, as shown below. auricle. CF PF OF (i) Pulmonary vein carries oxygenated blood from lungs to the heart. Concave mirror Convex lens (ii) Aorta takes blood from heart to all body 20. Given, m = 1.52, m = 1.0003, mw = 1.333 parts except lungs. g a (iii) Pulmonary artery takes deoxygenated As we know, m = Speed of light in vacuum blood from heart to lungs. Speed of light in medium 15. The given diagram shows contraction of right \\ m= c and left ventricles of heart. Due to contraction vm of right ventricle, blood is transferred to lungs for oxygenation through pulmonary artery. Due to contraction of left ventricle, oxygenated blood is pumped into various organs through aorta. Both these contractions take place simultaneously.

56 CBSE Sample Paper Science Class X (Term I) For glass, m = c = 1.52 …(i) 24. Generally, in case of a prism (ii), the formation g vg …(ii) of spectrum is shown below …(iii) For air, m = c = 1.0003 A a va For water, mw = c = 1.333 vw From Eq. (i), (ii) and (iii), we get OGrreaenngeYReeldlow Indigo Blue m >m >m C B Violet gwa In the above figure, from top the third colour is \\ c> c>c yellow. But we can see that from bottom the third colour is blue which is the colour of sky. vg vw va So we can obtain the correct situation by inverting the prism. Thus the required or va > vw > vg orientations can be found in case (ii). Hence, speed of light in air > speed of light in B C Violet water > speed of light in glass. Indigo Blue 21. Red light has the maximum wavelength and Green violet light has the minimum wavelength. Yellow Orange So in any medium, red light travels fastest and deviates least, while violet light travels slowest and deviates maximum, i.e. Wavelength µ Velocity µ 1 Deviation So, the angle of refraction of red light (r) is less A than the angle of refraction of violet light (v) [i.e. r < v]. 25. In step 1, limestone (CaCO3 ) is heated and calcium oxide and carbon dioxide are formed. 22. On observing the given figure, we notice that So, X is calcium oxide and the reaction is the object is placed at centre of curvature of endothermic because heat is given to the concave mirror. reactant. So, the image will be formed at center of In Step 2, the products formed in step 1, curvature and of same size as that of object but which are CaO and CO2 are treated with inverted, as shown below. water, then slaked lime is produced along with evolution of heat. So, step 2 involves A exothermic reaction. BF P B¢ C The complete reaction can be written as A¢ Limestone ¾H¾ea¾ted® CaO + CO 2 (CaCO3 ) endothermic Exothermic½ + H2O Latest CBSE SAMPLE PAPER So, the mirror has a focal length of - 3 cm and ¯ will produce an image of magnification - 1. Slaked lime + Heat 23. Q (Ca(OH)2 ) Air 26. The concentration of hydrogen ions is Glass P inversely related to its pH value according to O the following expression : Air pH = - log[H+ ] Normal at any point on the curved surface of So, according to graph, the pH value touched uniform hemisphere is along the radial line of the lowest in 2002. Hence, the concentration of that hemisphere because the tangent at that H+ ions is highest in 2002. point is perpendicular to the radius vector. So, the normal at point O in given figure is line OP. 27. When magnesium reacts with dil.HCl in test tube B, then there is formation of salt, i.e. As the incident ray from air travels along the MgCl2 and hydrogen gas comes out as bubbles. normal OP. Therefore, the angle of incidence This hydrogen gas bubbles are responsible for from air to glass at the point O on the the floating of magnesium metal. hemispherical glass slab is 0º. Mg + 2 HCl ¾® MgCl2 + H2 ­ (Dil. )

CBSE Sample Paper Science Class X (Term I) 57 28. The ionic compounds are crystalline solids and \\Both Assertion and Reason are true but hard in nature. Hence, they have high melting Reason is not correct explanation of Assertion. point and good conductor of electricity in aqueous form. So, according to the information 35. Amphoteric oxides are those oxides which given in table, B and C substances have high can act as both acid and base. melting points and good electrical conductivity in aqueous form. So, the element B and D form amphoteric oxides as they react with both acid and base So, B and C are ionic compounds. and evolve H2 gas. 29. Both (II) and (III) reasons are correct. Soap is 36. Single circulation is present in organisms with made up of a weak acid and a strong base, a 2-chambered heart, which is seen in fishes therefore, it is basic in nature and in basic such as shark, dog fish, Labeo and sting ray. medium, turmeric (natural indicator) gives reddish tinge. Turtle and frog have 3-chambered heart, whereas rabbit, parrot, pigeon, whale, penguin 30. In (I) setup, the electrolyte is dilute HCl and crocodile have 4-chambered heart. Hence, solution which can produce free ions on they do not show single circulation of blood in dissociation in water to conduct electricity. So, heart. the bulb will glow in this setup . 37. An extensive network of thin walled capillaries In (II) setup, the electrolyte is sugar solution richly supplied with blood is present around which does not conduct electricity as it does walls of alveoli and in glomerulus of nephron. not dissociate into free ions in water. Hence, the bulb will not glow. 38. Plants do not have specific organ for excretion. They use different strategies for removing their In (III) setup, the electrolyte is alcohol wastes such as excess water is removed by dissolved in water does not conduct electricity transpiration, some wastes are stored in leaves because it is very weak acid and does not that fall off from plants. Many plant’s waste dissociate completely into free ions. Hence, the products are stored in cellular vacuoles, and in bulb will not glow. form of resins and gums. They also excrete waste substances into the soil around them, In (IV) setup , the electrolyte is lime water but do not selectively filter toxic substances which contains citric acid and dissociates into through their leaves. free ions to conduct electricity. Hence, the bulb will glow. 39. Given, Power of lens, P = - 4 D 31. Assertion is true, but Reason is false because baking soda, being a base, increase the pH We know that, value of fresh milk to above 6. P = 100 f (cm) 32. Assertion is false, but Reason is true because the decomposition of vegetable matter into f (cm ) = 100 = 100 compost involves evolution of heat. P -4 Hence, it is an exothermic process. Þ f (cm ) = - 25 Latest CBSE SAMPLE PAPER Negative focal length means concave lens. 33. Assertion is true, but Reason is false. So, the lens is a concave lens of focal length In plants, waste products are stored as resins 25 cm. and gums in old xylem. They do not facilitate transport of water molecules. Elements of 40. When light rays from sun converge at a point xylem help in conduction of water. 15 cm from the mirror, this means 15 cm is focal length of concave mirror because rays 34. During the day time, sky appears blue. This is coming from infinity will converge at focus of because the size of the particles in the the mirror. atmosphere is smaller than the wavelength of visible light, so they scatter the light of shorter \\ f = - 15 cm wavelength, i.e. blue colour. This scattered blue light enters our eye. As the size of image is equal to the size of object, this means When a white light passes through a prism, it splits into seven colours, i.e. VIBGYOR. This m= -1 band of seven colours is called spectrum of or m = - v = - 1 white light. u Þ v=u

58 CBSE Sample Paper Science Class X (Term I) Therefore, object should be placed at centre of 45. The diagram of path of light travelling through curvature which makes an image at centre of different media is shown below, curvature of size. Medium 1 1 Hence, object should be 30 cm in front of the Medium 2 2 mirror. Medium 3 34 Medium 4 4 41. Yeast, mushroom and bread mould are saprotrophs. They breakdown food outside the Given, Ð1 = Ð3 = Ð4 and Ð2 < Ð1 body and absorb the simpler digested particles. Green plants are autotrophic in nature. Paramecium, Amoeba are organisms having holozoic mode of nutrition. Cuscuta, lice and tapeworm are parasitic organisms. 42. The major function of kidney tubules is Angle of incidence of medium 1 and angle of reabsorption of ions and molecules such as refraction of medium 3 are equal. sodium ions, glucose, amino acid, water, etc. If the tubule part of the nephron is not This shows that medium 1, medium 3 are same functioning at all in a person, the person will medium. produce dilute urine as absorption of water does not take place. As Ð2 < Ð1, means medium 2 is denser as compared to medium 1 that’s why light ray 43. Given, m = - 3 [Q real image is formed by bent towards the normal of the plane. convex lens] 46. Given, mglass = 1.65, m = 1.36 alcohol v = 80 cm Refractive index of flint glass w.r.t air = m \\ Magnification, m = v glass u Refractive index of alcohol w.r.t air = m alcohol Þ - 3 = 80 u Now, refractive index of flint glass w.r.t Þ u = - 80 cm alcohol 3 m = 1.65 = 1.21 = glass 1.36 m alcohol Hence, the candle should be placed at a 47. Given, èæç - 80 ÷øö distance of 3 cm from the lens. Focal length, f = + 10 cm [convex lens] 44. The complete diagram of image formation is Height of object, h0 = 2 mm = 0.2 cm given below : Object distance, u = - 5 cm Latest CBSE SAMPLE PAPER A Height of image, hi = ? B¢ By lens formula, C BF 1-1= 1 vu f A¢ On putting values, we get It is clearly observed that when object is placed 1- 1 = 1 between center of curvature and focus of v (- 5) 10 concave mirror then the image formed is beyond the centre of curvature which is real, 1 = 1 - 1 = 1-2 = -1 inverted and magnified. v 10 5 10 10 We know that a ray coming through centre of curvature of a concave mirror, reflects back Þ v = - 10 cm along the same path after striking the mirror surface. Now, magnification, m = v = hi The focal length of concave mirror is negative u h0 because it is measured along opposite to the direction of incident light from pole. or - 10 = hi Þ hi = 0.4 cm - 5 0.2 or hi = 4 mm So, the height of image is 4 mm.

CBSE Sample Paper Science Class X (Term I) 59 48. The elements X, Y and Z were dicarded for makes the experimental apparatus air tight usage by the company because for a cable whereas a suction pump will create vaccum by manufacturing, the element should be ductile, removing air from the container. malleable, good conductor of electricity and should have high melting point and the 57. As it is a clearly shown that ray 1 and ray 2 elements X, Y and Z do not have all these travel parallel to each other, before and after properties. Hence, X, Y and Z are dicarded. the refraction. This case is only possible in a parallel-sided glass block. 49. Metal carbonates on treating with acids, releases carbon dioxide and water along with 58. Given, Angle of incidence, i = 48.6º corresponding metal salt. Refraction index of box, m = 1.5 Hence, when calcium carbonates, CaCO3 reacts with acid like HCl, then calcium chloride, Now, using Snell’s law, we get CaCl2, carbon dioxide and water will be formed. sin i = m CaCO3(s) + HCl(aq) ¾® CaCl2( aq) + H2O(l) sin r + CO2(g) Þ sin 48.6 = 1.5 sin r 50. Mass of magnesium sulphate present in per gram solid = 6.0 g or sin r = 0.75 Þ r = sin-1(0.5) Total amount of salt obtained = 45 g 1.5 So, in 135 g of solid, or r = 30° Mass of magnesium sulphate = 135 ´ 6 = 18 g Hence, angle of refraction is 30º for refracted ray. 45 59. Light ray travels with different speed in 51. Brine is a high-concentration solution of salt, sodium chloride in water or it is the saturated different medium. The velocity of light in a solution of sodium chloride. medium depends on the refractive index of 52. Common salt is formed from hydrochloric acid and sodium hydroxide base. that medium. HCl + NaOH ¾® NaCl + H2O So, the acid used is strong acid which has pH m =c value between 1 to 3. m vm 53. The given experimental setup is used to prove or m µ1 the essentiality of carbon dioxide (CO2 ) for the m vm process of photosynthesis. More dense the medium, less the speed of light 54. The function of KOH in setup X is to absorb ray or vice-versa. carbon dioxide (CO2 ) present in the air. As compared to air, glass is optically denser 55. Iodine solution is used to test the presence of than air, hence speed of light ray in glass is less starch. KOH present in setup X absorbs CO2. than the speed of light ray in air. Thus, due to absence of CO2, the leaf fails to The ratio of sine of angle of incidence in the produce starch. Therefore, does not turn blue black in colour on treating with iodine first medium to the ratio of sine of angle of solution. refraction in the second medium, gives the In the leaf of plant Y, starch is synthesised due to availability of CO2, hence blue-black colour refractive index of the second medium w.r.t. would be obtained on treating with iodine solution. the first one, which is also known as Snell’s Latest CBSE SAMPLE PAPER 56. By placing the plants on glass plate and law. m applying vaseline to seal the bottom of jar 2 1m = = sin i 2 m sin r 1 Hence, III and V observations are correct. 60. If the object inside the box was made of a material with a refractive index less than 1.5, means the object inside the box becomes optically rarer as compared to previous material. Then the lateral shift of the rays would have been less, because of less angle of refraction.







SAMPLE PAPER 1 SCIENCE A Highly Simulated Practice Questions Paper for CBSE Class X (Term I) Examination Instructions Maximum Marks : 40 Time allowed : 90 Min. (i) This paper is divided into three Sections: (a) Section A – Contains 24 questions. Attempt any 20 questions. (b) Section B – Contains 24 questions. Attempt any 20 questions. (c) Section C – Contains 12 questions. Attempt any 10 questions. (ii) Each questions carries 0.80 mark. (iii) There is NO negative marking. Roll No. Section A Section-A consists of 24 questions. Attempt any 20 questions from this section. The first attempted 20 questions would be evaluated. 1. Vishal took 3 mL of potassium sulphate solution in a beaker and added approximately 3 mL of barium chloride solution. What would he observed? (a) Insoluble yellow precipitate was formed (b) Insoluble white precipitate was formed (c) Insoluble green precipitate was formed (d) The soluble become blue 2. In the given experimental diagram of electrolysis of water, the gases produced are Plastic mug Test tube Graphite rod Water Rubber stopper Anode Cathode Switch 6V Battery Electrolysis of water (a) hydrogen and carbon dioxide (b) oxygen and nitrogen (c) oxygen and hydrogen (d) carbon monoxide and hydrogen

64 CBSE Sample Paper Science Class X (Term I) 3. Which of the following represents correct balanced chemical equation? (a)AlCl3 + NH4OH ¾® Al(OH)3 + NH4Cl (b)AlCl3 + 3NH4OH ¾® Al(OH)3 + 3NH4Cl (c) 2AlCl3 + 3NH4OH ¾® 2 Al(OH)3 + 2 NH4Cl (d)3AlCl3 + 4NH4OH ¾® Al(OH)3 + NH4Cl 4. The element (X) reacts with acid and base, X ¾+¾A¾c¾id ® Y + H2 + Base Z + H2 Identify the correct option of element (X) with respect to reactivity with acid and base. Element ( X ) Reactivity with acid Reactivity with base (a) C O O (b) K O P (c) S P O (d) Zn P P 5. The graph given below depicts the reaction between acid and base, 14 B pH A value Volume of acid O added Which of the following solution or sample is responsible for decline in pH value of graph? (a) Caustic soda (b) Lemon juice (c) Baking soda (d) Common salt 6. In the given reaction, 2 PbO(s) + C(s) ¾® 2 Pb (s) + CO2(g) Identify the correct option which represents the substance oxidised and the reducing agent. Substance oxidised Reducing agent SAMPLE PAPER 1 (a) Pb PbO (b) PbO Pb (c) C C (d) CO2 PbO 7. The reaction between potassium bromide and silver nitrate is an example of (a) combination reaction (b) decomposition reaction (c) double displacement reaction (d) displacement reaction

CBSE Sample Paper Science Class X (Term I) 65 8. Which of the given options correctly represents the parent acid and base of sodium carbonate? Parent Acid Parent Base (a) HCl Na 2O NaOH (b) H2CO2 (c) H3PO4 Na 2O (d) H2CO3 NaOH 9. A substance ‘X’ turns blue litmus red. It also (a) turns phenolphthalein colourless (b) vanishes smell of clove oil (c) vanishes odour of vanilla (d) turns methyl orange to yellow 10. Which of the following is an endothermic process? (a) Condensation of water vapours (b) Dilution of sulphuric acid (c) Evaporation of water (d) Combustion of LPG 11. The given diagram shows a vertical section of the heart. 1 3 2 4 Which of the following function of the numbered blood vessels are correctly matched? SAMPLE PAPER 1 (a) 1-Pulmonary artery–Carries blood to the body (b) 2-Superior and inferior vena cava–Carries blood to lungs (c) 3-Aorta–Carries blood from lungs (d) 4-Pulmonary veins–Carries blood from lungs 12. A person was found to have reduced level of reabsorption of water and glucose due to kidney damage. Which of following labelled parts would be the site of damage for this patient ? Q P S (a) Q R (c) S (b) P (d) R

66 CBSE Sample Paper Science Class X (Term I) 13. High blood pressure is caused by the (a) constriction of ventricles (b) constriction of arterioles (c) constriction of veins (d) constriction of capillaries 14. The overall process of breakdown of glucose in both aerobic and anaerobic respiration is summarised below. Identify the correct option regarding the following labels. Glucose Absence of Ethanol + Carbon dioxide + Energy (6-carbon oxygen (2-carbon molecule) molecule) (ii) (i) Pyruvate Lack of oxygen (3-carbon Lactic acid + Energy molecule (iii) (3-carbon molecule) + Energy) Presence of oxygen Carbon dioxide + (iv) Water + Energy (a) Process (i) occurs in mitochondria in the absence of oxygen (b) Process (iv) occurs in mitochondria in the presence of oxygen (c) In the absence of oxygen, formation of ethanol, carbon dioxide and energy occur in bacteria (ii) (d) Process (iii) occurs in blood cells during heavy exercise 15. Which of the following statement is true about heart? Vena cava receiving Aorta blood from upper body Pulmonary arteries Right atrium Pulmonary veins Vena cava receiving blood from Left atrium lower body Valves Right ventricle Left ventricle SAMPLE PAPER 1 Interventricular septum(dividing wall) (a) Left atrium receives oxygenated blood from different parts of body, while right atrium receives deoxygenated blood from lungs (b) Left ventricle pumps oxygenated blood to different body parts, while right ventricle pumps deoxygenated blood to lungs (c) Left atrium transfers oxygenated blood to right ventricle which sends it to different body parts (d) Right atrium receives deoxygenated blood from different parts of the body, while right ventricle pumps oxygenated blood to different parts of the body

CBSE Sample Paper Science Class X (Term I) 67 16. Observe the diagram of human respiratory system. C B A D Match the labelling referred in Column I and correlate it with Column II. Column I Column II A. 1. These are the main passageway into the lungs. B. 2. They deliver air to tiny air sacs called alveoli. C. 3. It is also known as windpipe. D. 4. It is the passage way between pharynx and trachea. Codes AB C D ABC D (b) 3 2 1 4 (a) 2 3 4 1 (d) 1 2 3 4 (c) 1 4 3 2 17. Which phenomenon is depicted in the diagram given below? Star Observer (a) Diffraction of light (b) Scattering of light (c) Refraction of light (d) Reflection of light 18. Identify the optical element which forms a real magnified image and virtual magnified SAMPLE PAPER 1 image of an object in front of it. (a) A thin diverging lens (b) A thin converging lens (c) A thick diverging mirror (d) A thick converging mirror 19. A real image of same size as that of object is formed by a convex lens. The object must be at a distance of (a) u < f (b) u = f (c) f < u < 2 f (d) u = 2 f

68 CBSE Sample Paper Science Class X (Term I) 20. Medium A Medium B Observe the above figure. Which of the following statement would be correct? (a) Medium B has more refractive index than medium A. (b) Medium A is optically denser medium as compared to medium B. (c) Medium A and medium B are essentially the same medium but angle of incidence is critical angle. (d) Medium A is denser, so it is optically rarer medium. 21. Refractive index of water with respect to air is 1.33, and refractive index of diamond with respect to air is 2.42. Based on this data, arrange the wavelength of light through them in increasing order. (a) Wavelength in air < Wavelength in diamond < Wavelength in water (b) Wavelength in water < Wavelength in air < Wavelength in diamond (c) Wavelength in diamond < Wavelength in water < Wavelength in air (d) Wavelength in air < Wavelength in water < Wavelength in diamond 22. SAMPLE PAPER 1 Black paper The focal length of above lens is 10 cm. One-half of lens is covered with black paper. Which of the following is correct? (a) The image formed is half of original image in height (b) A complete image is formed but of less intensity and brightness (c) Image is formed only above the principal axis (d) No image is formed due to black paper 23. Red colour is used for stop sign in the traffic signal. Which phenomenon is involved in this ? (a) Dispersion of white light into its constituent colours (b) Refraction of light due to atmosphere (c) Reflection of light due to windshield of car (d) Scattering of light by particles present in air 24. Reflected ray A ray is reflected by a plane mirror as shown above. The angle of incidence for the above reflected ray is (a) 90° (b) 0° (c) 180° (d) 45°

CBSE Sample Paper Science Class X (Term I) 69 Section B Section B consists of 24 questions (Sl. No. 25 to 48). Attempt any 20 questions from this section. The first attempted 20 questions would be evaluated. 25. The table provides the pH value of four solutions, P, Q, R and S. Solutions pH value P 3 Q 10 R 5 S 12 Which of the following correctly represents the arrangements of solutions in decreasing order of the concentration of hydrogen ions? (a) P > Q > R > S (b) S > Q > R > P (c) P > R > Q > S (d) P < S < Q < R 26. A student performed the following four experiments, CuSO4 (aq) CuSO4 (aq) Al Zn I II CuSO4 (aq) CuSO4 (aq) Fe Cu III IV In which experiment(s) would he find the formation of a solid deposition? (a) I and II (b) II and III (c) I, II and III (d) Only IV 27. The table shown below gives information about four substances: A, B, C and D. Substances Hardness Ductility Lustrous A Hard Yes Yes B Soft No Yes SAMPLE PAPER 1 C Hard Yes Yes D Soft Yes Yes Identify the non-metal from the above given substances. (a) A, C (b) B, D (c) Only B (d) None of these

70 CBSE Sample Paper Science Class X (Term I) 28. Copper (II) hydroxide on decomposition, gives two products. Which of the following statement is correct regarding the balanced chemical equation for this process? (a) 2 moles of copper (II) hydroxide produces 2 moles of cupric oxide and 1 mole of water (b) 1 mole of copper (II) hydroxide produces 2 moles of cupric oxide and 1 mole of water (c) 1 mole of copper (II) hydroxide produces 1 mole of cupric oxide and 1 mole of water (d) 2 moles of copper (II) hydroxide produces 1 mole of cupric oxide and 2 moles of water 29. Equal length of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid (HCl) is added to test tube A, while acetic acid (CH3COOH) is added to test tube B. Amount and concentration taken for both the acids are same. Which of the following observation(s) is/are correct? I. Change in colour is observed in both test tubes. II. Fizzing occurs in both test tubes. III. Evolution of hydrogen gas in both test tubes. IV. White precipitate is formed in test tube A. (a) I and III (b) II and III (c) I and IV (d) I, II and III 30. Four samples, A, B, C and D were taken and their pH value was recorded. The graph was drawn on the basis of pH value with respect to four samples. 14 pH 7 value 0A B C D Which sample represents milk of magnesia? (a) A (b) B (c) C (d) D Direction (Q. No. 31 to 34) Consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below : (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true, but R is not the correct explanation of A. (c) A is true, but R is false. (d) A is false, but R is true. SAMPLE PAPER 1 31. Assertion The balancing of chemical equation is based on law of conservation of mass. Reaction In a balanced equation, the total number of atoms of each elements must be equal on both sides of the equation. 32. Assertion Baking soda is an acid which creates acidity in the stomach. Reason Baking soda has a pH around 8.3. 33. Assertion The inner lining of the small intestine have numerous finger-like projections called villi. Reason The villi helps in breakdown of protein and lipids. 34. Assertion Out of water, mustard oil, glycerine and kerosene, the ray of light incident obliquely at same angle would bend most in glycerine. Reason Glycerine has lowest refractive index.

CBSE Sample Paper Science Class X (Term I) 71 35. The table given below shows the displacement reaction of a few elements, A, B, C and D with following solutions one by one. Metal Copper sulphate Zinc sulphate Silver nitrate A PO P B PP P C OO P D OO O Arrange the metals A, B, C and D in order of increasing reactivity. (a) A > B > C > D (b) D > C > B > A (c) D < C < A < B (d) B < A < C < D 36. Pancreatic enzymes helps in the digestion of (a) fats and proteins (b) carbohydrates and proteins (c) carbohydrates, proteins and fats (d) carbohydrates and fats 37. Which of the following statement is correct about bile? (a) Secreted by liver and stored in gall bladder (b) Secreted by pancreas and stored in liver (c) Secreted by salivary gland and stored in saliva (d) Secreted by gastric glands and stored in stomach 38. What is the importance of having many blood vessels in the walls of the small intestine ? (a) The blood vessels absorbs water from undigested food (b) The blood vesels carry the digestive juices (c) It enables the efficient absorption of digested food (d) It takes the absorbed food to each cell for obtaining energy 39. Light rays from a distant source are converged at a point 20 cm in front of a concave mirror. Where should an object be placed, so that size of its image is equal to the size of the object? (a) 40 cm in front of concave mirror (b) 20 cm in front of concave mirror (c) Between 20 cm and 40 cm in front of concave mirror (d) More than 40 cm in front of concave mirror 40. If two thin lenses of focal length 20 cm and - 25 cm are combined to form a single lens, then the power of combination is (a) 5 D (b) 1 D SAMPLE PAPER 1 (c) - 4 D (d) 9 D 41. During the breathing cycle, when air is taken in and let out, the lungs always contain (a) total volume of air (b) tidal volume (c) expiratory reserve volume (d) residual volume of air 42. Anam choked when she was taking her lunch. What could have happened? (a) She swallowed food that was not completely digested (b) The salivary gland have not secreted enough amylase enzyme (c) Some food particles entered her windpipe (d) Starch is not digested properly in her mouth

72 CBSE Sample Paper Science Class X (Term I) 43. A A' B B' F C An object AB is standing 40 cm in front of diverging mirror. Its image appears 15 cm behind the mirror. The focal length of the mirror will be (a) + 12 cm (b) - 12 cm (c) + 24 cm (d) - 24 cm 44. A 6 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 25 cm. The distance of the object from the lens is 40 cm. Find the size of the image formed. (a) + 66.67 cm (b) - 10 cm (c) - 66.67 cm (d) + 10 cm 45. A B The above optical element is a spherical mirror which produces an image of magnification -1 on a screen placed at a distance of 50 cm from the mirror. Find the distance of the image from the object. (b) - 50 cm (a) 25 cm (c) 50 cm (d) 0 46. If the speed of light in air is 3 ´ 108 m/s and speed of light in water is 2.2 ´ 108 m/s, then the refractive index of water is (a) 1.4 (b) 2.4 (c) 1.5 (d) 1.22 47. Two media are joined together in contact and a ray of light travels as shown in the figure. 45º Medium 1 30º Medium 2 SAMPLE PAPER 1 Then, the refractive index of medium 1 with respect to medium 2 is (a) 3 (b) 3 2 (c) 2 (d) 1 3 2

CBSE Sample Paper Science Class X (Term I) 73 48. Zinc granules were added to zinc sulphate, copper sulphate, aluminium sulphate and iron sulphate solution as shown below. Zinc Copper sulphate sulphate Zinc Zinc I II Aluminium Iron sulphate sulphate Zinc Zinc III IV Which of the following observation is correct? (a) In beaker II, zinc will displace copper from copper sulphate solution. (b) In beaker III, zinc will displace aluminium from aluminium sulphate solution. (c) In beaker IV, zinc will not displace iron from its sulphate solution. (d) All of these are correct. Section C This Section C consists of three Cases followed by questions. There are a total of 12 questions in this section. Attempt any 10 questions from this section. The first attempted 10 questions would be evaluated. Case I. Four groups of students were assigned on separately the experiment of interaction of iron nail with a solution of copper sulphate. Each group recorded the observations as given below in the table. Group of Initial colour Final colour Change in the students of solution of solution iron nail A Blue Colourless Brown coat B Green Green Brown coat C Blue Blue Brown coat D Blue Light green Brown coat 49. Which type of reaction is observed in given experiment ? (a) Combination (b) Displacement (c) Double displacement (d) Decomposition 50. Which group of students recorded all the observations correctly? SAMPLE PAPER 1 (a) A (b) B (c) C (d) D 51. The brown coating on iron nail is due to (b) copper deposition (d) All of these (a) rust (c) oxidation

74 CBSE Sample Paper Science Class X (Term I) 52. Which of the following statement is correct? (a) Iron is more reactive than copper (b) Copper is more reactive than iron (c) The colour of iron sulphate solution is blue (d) The colour of copper sulphate solution is green Case II. Excretion is the biological process by which an organism removes the metabolic wastes from the body. The main organs involved in the human excretory systems are pair of kidneys, a pair of ureters, a urinary bladder and a urethra. The figure given below represents the human excretory system. Ureter Kidneys Urinary bladder 53. Where can one find kidneys in a human body? (a) At the back, behind the lungs (b) At the back, above the waist (c) Near belly button (d) Behind pancreas gland 54. The muscular tubes which take the urine from the kidneys to the bladder are (a) urinary bladder (b) ureters (c) urethra (d) nephrons 55. Choose the incorrect pair. (b) Transport of urine—Ureter (d) Collecting filtered urine—Glomerulus (a) Storage of urine—Urinary bladder (c) Filtration units—Kidney 56. Which among the following is/are not the function of kidney? I. Cleaning of blood by filtering it and removing waste products. II. Regulation of minerals in the body and production of hormones. III. Providing energy for the flow of blood. IV. Maintaining higher concentration of electrolytes. Codes (a) I and III (b) II and III (c) Only II (d) III and IV SAMPLE PAPER 1 Case III. Vinita demonstrated an activity to prove that white light is made up of many colours. She set up the experiment as shown White A Spectrum light of different colours She observed that white light gets split into raindows colours. Some deviates more while some deviates less.

CBSE Sample Paper Science Class X (Term I) 75 57. Which optical element A is used by Vinita to perform this experiment? (a) Soap bubble (b) Rectangular glass slab (c) Prism (d) Diverging lens 58. She observes that there are seven colours in the spectrum, then which colour suffers least deviation and most deviation, respectively? (a) Red colour suffers least deviation while violet colour suffers most deviation. (b) Violet colour suffers least deviation while red colour suffers most deviation. (c) Yellow colour is mean colour, so it suffers minimum deviation. (d) Yellow colour is mean colour, so it suffers most deviation. 59. Four colour rays are shown in figure. Which colour has more speed in the prism ? Beam of P light Q R S (a) P (b) Q (c) R (d) S 60. Among the seven colours observed in the experiment, which colour is having the shortest wavelength? (a) Red (b) Blue (c) Yellow (d) Violet SAMPLE PAPER 1

OMR SHEET SP 1 Roll No. Sub Code. Student Name Instructions Use black or blue ball point pens and avoid Gel & Fountain pens for filling the OMR sheet. Darken the bubbles completely. Don’t put a tick mark or a cross mark, half-filled or over-filled bubbles will not be read by the software.  Correct Incorrect Incorrect Incorrect Do not write anything on the OMR Sheet. Multiple markings are invalid. 1 21 41 2 22 42 3 23 43 4 24 44 5 25 45 6 26 46 7 27 47 8 28 48 9 29 49 10 30 50 11 31 51 12 32 52 13 33 53 14 34 54 15 35 55 16 36 56 17 37 57 18 38 58 19 39 59 20 40 60 Check Your Performance Score Percentage = Total Correct Questions 100 Total Questions: × Total Correct Questions: Total Questions Less than 60% > Average (Revise the concepts again) If Your Score is Greater than 60% but less than 75% > Good (Do more practice) Above 75% > Excellent (Keep it on)

CBSE Sample Paper Science Class X (Term I) 77 Answers 1. (b) 2. (c) 3. (b) 4. (d) 5. (b) 6. (c) 7. (c) 8. (d) 9. (a) 10. (c) 11. (d) 12. (d) 13. (b) 14. (b) 15. (b) 16. (a) 17. (c) 18. (b) 19. (d) 20. (b) 21. (c) 22. (b) 23. (d) 24. (b) 25. (c) 26. (c) 27. (c) 28. (c) 29. (b) 30. (b) 31. (a) 32. (d) 33. (c) 34. (c) 35. (c) 36. (c) 37. (a) 38. (d) 39. (a) 40. (b) 41. (d) 42. (c) 43. (c) 44. (b) 45. (d) 46. (a) 47. (c) 48. (a) 49. (b) 50. (d) 51. (b) 52. (a) 53. (b) 54. (b) 55. (c) 56. (d) 57. (c) 58. (a) 59. (a) 60. (d) EXPLANATIONS 1. When potassium sulphate solution was added AgNO3(aq) + KBr(aq) ¾® AgBr(s) to barium chloride solution, then white precipitate of barium sulphate is formed along Silver nitrate Potassium bromide Silver bromide with potassium chloride. + KNO3(aq) Potassium nitrate K2SO4(aq) + BaCl2(aq) ¾® BaSO4(s) This reaction is an example of double displacement reaction as Ag and K are Potassium sulphate Barium chloride Barium sulphate displaced by each other. (white ppt.) + 2KCl(aq) 8. Sodium carbonate is prepared by reaction Potassium chloride between carbonic acid (H2CO3 ) as parent acid and sodium hydroxide (NaOH) as parent 2. The electrolysis of water forms two gases, hydrogen and oxygen. base. 2H2O(l) ¾E¾lec¾trol¾y¾sis® 2 H2(g) +O2(g) 2NaOH + H2CO3 ¾® Sodium hydroxide Carbonic acid 3. Chemical equation (b) is balanced one. Na2CO3 + 2H2O The balanced chemical equation is that in which Sodium carbonate Water the total number of atoms of each element are equal on both sides of the equation. 9. A substance ‘X’ which turns blue litmus red is AlCl3 + 3NH4OH ¾® Al(OH)3 + 3NH4Cl an acid and phenolphthalein becomes colourless in presence of acid. 4. The element (X) is zinc which reacts with both acid and base. Whereas methyl orange gives yellow colour in basic solution. Vanilla and clove are olfactory Zn(s) + H2SO4(aq) ¾® ZnSO4(aq) + H2(g) indicators, their smell can be detected in presence of acid only. Zinc Sulphuric acid Zinc sulphate Hydrogen 10. Evaporation of water is endothermic process Zn(s) + 2NaOH(aq) ¾® Na2ZnO2(aq) + H2(g) because in this process, heat is required for conversion of water into vapours. Zinc Sodium hydroxide Sodium zincate Hydrogen 11. 1-Pulmonary artery carries blood from the 5. Lemon juice (b) contain citric acid. Acids have heart to the lungs. pH value below 7. So, addition of lemon juice is responsible for the decline in pH value in the 2-Superior and inferior vena cava carries given graph. deoxygenated blood from the body to the heart. Caustic soda and baking soda are bases which 3-Aorta carries blood from the heart to the body. SAMPLE PAPER 1 can increase pH value and common salt solution is neutral in nature. 4-Pulmonary veins carries blood from lungs to the heart. 6. The substance which gets oxidised acts as reducing agent. C is oxidised in the given 12. The correct labelling is reaction by addition of oxygen atom, therefore P = Efferent arteriole also acts as reducing agent. Q = Glomerulus R = Capillaries 7. The reaction between potassium bromide and S = Collecting duct silver nitrate forms two products that are silver bromide and potassium nitrate.

78 CBSE Sample Paper Science Class X (Term I) The capillaries (R) around the kidney tubule 17. When the light from a star enters the earth’s reabsorbing some useful substances from the atmosphere, it undergoes multiple refraction initial filtrate like glucose, amino acids, water and its path changes multiple times due to as the urine flows along the tubule. bending of light towards the normal. 13. High blood pressure or hypertension is caused Therefore, the apparent position of the star is by the constriction of arterioles, which results in slightly different from its actual position. increased resistance to blood flow. It can lead to the rupture of an artery and internal bleeding. 18. A thin converging lens forms a real magnified and virtual magnified image. 14. Process (iv) occurs in mitochondria in the When object is placed between F and 2F, presence of oxygen. it forms real and magnified image but inverted. Breakdown of pyruvate using oxygen takes place in the mitochondria. This process breaks When object is placed between optical centre up the three-carbon pyruvate molecule to give and F, it forms virtual, erect and magnified three molecules of carbon dioxide and water. image. The incorrect options can be corrected as 19. Convex lens forms a real image of same size as l Process (i) occurs in cytoplasm in the that of object when the object is placed at its presence or absence of oxygen. centre of curvature, means object distance, l In the absence of oxygen, formation of u = 2 f. ethanol, carbon dioxide and energy occur in yeast (ii). 20. According to the given figure, light ray coming from medium B enters medium A and bends l Process (iii) occurs in muscle cells during towards normal which means medium A is heavy exercise. optically denser than medium B. 15. Oxygen-rich blood from lungs enters the left As the medium A is optically denser, so its atrium. The left atrium will relax when it is refractive index is more than that of B. collecting this blood. It then contracts, and the left ventricle (next chamber) expands so that 21. As we know that, the blood is transfered to it. Contraction of left ventricle pumps the oxygenated blood to the Refractive index µ 1 various parts of body. Wavelength Deoxygenated blood from body enters right \\ ma < mw < md atrium as it expands. Now, as the right atrium Þ ld < lw < la contracts, the right ventricle (lower chamber) dilates resulting in transfer of blood to right Wavelength of light in diamond is smallest ventricle. while wavelength of light in air is largest. 16. The correct labelling is 22. When half of lens is covered with black paper, then the image formation is shown below (A)—Bronchioles (B)—Trachea A (C)—Larynx (D)—Bronchi (A) Bronchi are subdivided into smaller tubes F B' 2F and form structure called bronchioles. Each bronchioles finally terminates into alveoli B 2F F that provide surface for the exchange of SAMPLE PAPER 1 gases. A' (B) Trachea is also called windpipe which Lens formed a complete image of the object, serves as passage for air to the lungs. but the intensity and brightness of image will be reduced because some rays cannot pass (C) Larynx is also called voice box. It is the through covered portion of lens. passage way of air between pharynx and trachea. 23. Traffic signals are of red colour because red light is least scattered and enters into the eye (D) Trachea is divided into two smaller tubes with less loss of intensity. Due to this reason, called bronchi, which are main observer can see red signal from a very far passageway into the lungs. distance.

CBSE Sample Paper Science Class X (Term I) 79 24. The angle of incidence for the given reflected The inner lining of the small intestine have light is 0°. The ray diagram is shown below numerous finger-like projections called villi. These villi increases the surface area for Reflected ray absorption. The villi are richly supplied with blood vessels which takes the absorbed food to Incident ray each and every cell of the body, where it is utilised for obtaining energy, building up new 25. Lower the pH value of a substance, higher the tissues and the repair of old tissues. concentration of hydrogen ions. H+ ion concentration decreases as the pH 34. A is true, but R is false because the refractive value increases. index of glycerine is highest among the given So, the decreasing order of concentration of materials, so the ray of light incident obliquely hydrogen ions of P, Q, R, and S is P > R > Q > at same angle would bend most in case of S. glycerine. 26. In I, II and III experiments, he find the 35. B is the only metal which shows displacement formation of a solid deposition because Al, Zn reaction in all three given solution of copper, and Fe are more reactive than Cu. They will zinc and silver. This indicates that B is more replace Cu from its sulphate solution and Cu reactive than rest of metals and D is least will deposit as solid. reactive as it does not show any displacement reaction with given three solutions. A shows 27. As non-metals are soft and non-ductile in displacement reaction in two solution while C nature. They are non-lustrous but iodine is a shows in only one solution. Therefore, A is non-metal which is lustrous in nature. Hence, more reactive than C but less reactive than B. B is a non-metal among other options. Hence, the increasing order of reactivity is 28. On decomposition of 1 mole of copper (II) D<C<A<B hydroxide, it gives 1 mole cupric oxide and 1 mole water. 36. The pancreatic enzymes are released in small Cu(OH)2 ¾¾D® CuO + H2O intestine, which is the site for complete All elements are already balanced in this digestion of carbohydrates, proteins and fats. equation. So, (c) is the correct answer 37. Bile juice is secreted by liver and stored in the 29. When metal reacts with acid, there is gall bladder. Bile salts breakdown the large fat formation of salt and hydrogen gas. globules into smaller globules increasing the Metal + Acid ¾® Salt + Hydrogen gas efficiency of enzymes action, i.e. emulsification. This hydrogen gas is responsible for fizzing that occur in both test tubes. So, II and III are 38. The villi in the small intestine are supplied with correct observations. blood vessels which takes the absorbed food to each and every cell of the body, where it is 30. Milk of magnesia is basic in nature and have utilised for obtaining energy, building up new pH value around 10.5. So, according to bar tissues and the repair of old tissues. graph, only B have pH value above 7. Hence, B represents milk of magnesia as their pH 39. Light rays from a distant source converge at value is higher than 7. 20 cm in front of a concave mirror, this means 20 cm is the focal length of that mirror. 31. Both A and R are true and R is the correct Therefore, to get an image of same size of explanation of A. object, the object should be placed at centre of curvature, i.e. 40 cm in front of concave mirror. The balancing of equation follows law of conservation of mass which states that total 40. Given, f1 = 20 cm and f2 = - 25 cm SAMPLE PAPER 1 mass of all atoms is same before and after the We know that, P = 100 reaction means mass is conserved. f (in cm) 32. A is false but R is true. \\ P1 = 100 = 5 D Baking soda is a base which has pH value 20 around 8.3. and P2 = 100 = - 4 D 33. A is true, but R is false. - 25 Power of combination, P = P1 + P2 = 5 D - 4 D Þ P =1D

80 CBSE Sample Paper Science Class X (Term I) 41. During the breathing cycle, when air is taken \\ Refractive index, m = va in and let out, the lungs always contain a vw residual volume of air, so that there is sufficient time for oxygen to be absorbed and Þ m = 3 ´ 108 = 1.4 for the carbon dioxide to be released. 2.2 ´ 108 42. A cartilage flap, epiglottis is present in the 47. Given, angle of incidence, i = 45° throat behind the tongue, which prevents the Angle of refraction, r = 60° entry of food particles into the windpipe. 45º Medium 1 While swallowing food epiglottis moves to Medium 2 block the entrance of food into the windpipe. 30º 60º Sometimes, food might enter into windpipe and cause choking. Thus, Anam choked due to \\Refractive index of medium 1 w.r.t. medium 2, entry of food particles in her windpipe. m = sin i (by Snell’s law) 43. Given, object distance, u = - 40 cm sin r 1 Image distance, v = 15 cm Þ m = sin 45° Þ m = 2 By using mirror formula, we get sin 60° 3 1+1= 1 uv f Þ m= 2 2 3 Þ 1 + 1 =1 - 40 15 f 48. According to reactivity series, aluminium is more reactive than zinc. So, zinc cannot or 1 = 5 displace aluminium, but iron and copper are f 120 less reactive than zinc. So, they can be easily displaced by zinc. So, the correct observation or f = + 24 cm is (a). 44. Given, height of object, ho = 6 cm 49. The change in colour of initial and final solution and the deposition of layer on element Focal length of lens, f = 25 cm indicates the occurrence of displacement Object distance, u = - 40 cm reaction. Using lens formula, 1 = 1 - 1 50. The blue colour of copper sulphate changes f vu into light green colour solution due to formation of ferrous sulphate by displacement Þ 1 =1- 1 reaction. 25 v (- 40) Fe(s) + CuSO4(aq) ¾® FeSO4(aq) + Cu(s) or v = 200 cm 3 Iron Copper sulphate Ferrous sulphate Copper Now, magnification, m = hi = v (Blue) (Light green) ho u The displaced copper gets deposited on iron hi = 200 nail and form brown coating on it. 6 3 ´ (- 40) Þ hi = - 10 cm 45. The mirror is concave mirror. Hence, D group of students recorded all the correct observations. SAMPLE PAPER 1 \\GiMveang,nmif=ica-ti1o, nu,=m-=5-0 cm -v vÞ - 1= - 50 51. The brown coating on iron nail is due copper deposition because according to reactivity u series, iron is more reactive than copper, so, it will displace copper from it’s sulphate solution Þ v = - 50 cm and then solid copper will get deposited on \\ The distance of image from the object iron nail. = - 50 - (- 50) = 0 52. According to reactivity series, iron is more 46. Given, speed of light in air (va ) = 3 ´ 108 m/s reactive than copper as it is placed above copper in reactivity series of metals. Speed of light in water (vw) = 2.2 ´ 108 m/s

CBSE Sample Paper Science Class X (Term I) 81 53. In humans, the kidneys are the main excretory erythropoietin. Kidney also regulaes the pH organs. These bean-shaped organs are located in of blood and maintains homeostasis. abdomen, one on either side of backbone above the waist. 57. Prism is the optical element, which is used in this experiment to get spectrum of white 54. The urine forming in each kidney eventually enters light. a long muscular tube, the ureter, which connects the kidneys with the urinary bladder. 58. Red colour suffers least deviation because the wavelength of red light is more than 55. Each kidney has large numbers of tiny filtration rest of the colours and violet colour suffers unit called nephrons, which are closely packed from most deviation due to its shorter together. These are the structural and functional wavelength. units of kidney. 59. P has more speed in the prism because it 56. Kidneys are involved in the cleaning of blood by suffers least deviation. filtering it and removing waste products. It also regulates minerals in our body and produced 60. Violet colour has the shortest wavelength certain hormones like vitamin-D and among rest of the colours in white light. SAMPLE PAPER 1

SAMPLE PAPER 2 SCIENCE A Highly Simulated Practice Questions Paper for CBSE Class X (Term I) Examination Instructions Maximum Marks : 40 Time allowed : 90 Min. (i) This paper is divided into three Sections: (a) Section A – Contains 24 questions. Attempt any 20 questions. (b) Section B – Contains 24 questions. Attempt any 20 questions. (c) Section C – Contains 12 questions. Attempt any 10 questions. (ii) Each questions carries 0.80 mark. (iii) There is NO negative marking. Roll No. Section A This section consists of 24 multiple choice questions with overall choice to attempt any 20 questions. The first attempted 20 questions will be considered for evaluation. 1. Ajay took lead nitrate salt in a dry test tube. He heated the test tube. What would he observed? (a) Yellow coloured residue and brown fumes were observed (b) White coloured residue with yellow fumes were observed (c) Yellow precipitate with colourless residue was observed (d) Brown coloured fumes with colourless residue was observed 2. Identify the colour of gas evolved in the following experiment. Test tube holder Gas evolved Potassium nitrate Boiling test tube Burner (a) Colourless (b) Yellow (c) Whitish grey (d) Black

CBSE Sample Paper Science Class X (Term I) 83 3. Metal NaOH Metal salt Gas Which of the following two combinations are correct? Metal Gas evolved (i) Al No (ii) Ag No (iii) Mg Yes (iv) Zn Yes (a) (i) and (iii) (b) (ii) and (iii) (c) (ii) and (iv) (d) (i) and (iv) 4. Which of the following option correctly represents a balanced chemical equation? (a) 2Na2CO3 (s) + 2HCl(aq) ¾® 2NaCl(aq) + H2O(c) + 2CO2(g) (b) 3Na2CO3 (s) + HCl(aq) ¾® 3NaCl(aq) + H2O(l) + 3CO2(g) (c) Na2CO3 (s) + 2HCl(aq) ¾® 2NaCl(aq) + H2O(l) + CO2(g) (d) 3Na2CO3 (s) + 2HCl(aq) ¾® 3NaCl(aq) + H2O(l) + 3CO2(g) 5. The graph given below represents neutralisation reaction. The pH of solution changes as we add excess of base to an acid. D 14 pH C value 7 B A 0 Volume of base added Which letter denotes the area of the graph where both base and salt are present? (a) A (b) B (c) C (d) D 6. In the reaction of copper oxide with hydrogen, SAMPLE PAPER 2 CuO(s) + H 2(g) ¾® Cu(s) + H 2O(l) Which option in the given table correctly represents the substance oxidised and the reducing agent? Substance oxidised Reducing agent (a) CuO Cu (b) H2 H2 (c) Cu CuO (d) H2O H2

84 CBSE Sample Paper Science Class X (Term I) 7. The chemical reaction between methane and oxygen is (a) displacement reaction (b) combination reaction (c) exothermic reaction (d) precipitation reaction 8. Which of the given option correctly represents the parent acid and parent base of ammonium chloride? Parent acid Parent base (a) NH3 NaOH (b) HCl (c) HNO3 NH3 (d) HCl NaOH NH4 OH 9. What happens when excess of CO 2 gas is passed through lime solution (lime water)? (a) The milkiness of limewater disappears (b) The milkiness of limewater changes from white to yellow (c) The lime solution becomes hot (d) The lime solution becomes cold 10. The bleaching powder gives smell of chlorine due to (a) formation of chlorine on exposure to atmosphere (b) unstability of bleaching powder (d) formation of excess of chlorine (d) displacement reaction 11. Observe the diagram of human respiratory system, Nose Nasal Pharynx passage Larynx (i) Bronchi Rings of cartilage (iii) Lung Respiratory bronchioles SAMPLE PAPER 2 (iv) (ii) Select the option which gives correct identification and main function or/and characteristics. (a) (i) Trachea - It is supported by complete cartilage rings (b) (ii) Diaphragm - Relaxes and get back to its original shape during expiration (c) (iii) Ribs - When we breathe out, ribs are lifted (d) (iv) Alveoli - It filters air by fine hairs and mucus present in them

CBSE Sample Paper Science Class X (Term I) 85 12. The table show nutrients present in four foods. Food Carbohydrate Fat Protein P üû ü Q ûû ü R ûü û S üü û Which foods would both be partly digested in the stomach? (a) P and Q (b) P and R (c) Q and S (d) R and S 13. Rings of cartilage are present in the throat to ensure that (a) the air passage collapses (b) the air passage does not collapse (c) the air is filtered entering the nostrils (d) None of these 14. The given diagram shows the different stages of nutrition in Amoeba with labels (i) to (iv). Nucleus (i ) Pseudopodia Food particle Food vacuole (ii ) Food particle (iii ) (iv ) Undigested food removed Identify the correct label with its characteristics. (a) (i) Ingestion – It is the process of eliminating undigested food (b) (ii) Digestion – The food get readily absorbed by the cytoplasm (c) (iii) Absorption – The cell membrane ruptures and absorbs food (d) (iv) Egestion – The undigested food is removed from the body 15. Identify the phase of respiration which is represented in the diagram given below. Sternum SAMPLE PAPER 2 Ribs Lung Diaphragm

86 CBSE Sample Paper Science Class X (Term I) Arrow indicates the expansion of different parts shown. (a) When we breathe in, then the ribcage and diaphragm moves upward simultaneously (b) When we breathe in, ribcage contracts and diaphragm relaxes (c) When we breathe in, the downward movement of ribcage and upward movement of diaphragm increase the chest cavity (d) When we breathe in, the upward movement of ribcage as well as downward movement of diaphragm increase the space in chest cavity 16. Nephron, functional unit of kidney, the structure that actually produces urine in the process of removing waste and excess substances from the blood. A B C Renal D artery Brach of renal vein Capillaries Match the labelling referred in Column I and correlate with the Column II. Column I Column II A 1. It is network of small blood vessels, located at the beginning of the nephron. It finally gathers all the materials that has not returned to the blood through the B 2. tubular membranes. C 3. Reabsorption of glucose, amino acids and major amount of water occurs in it. D 4. It is cup-like structure that filters blood from the urine. Codes ABC D A B CD (b) 4 3 1 2 (d) 4 2 1 3 (a) 4 3 2 1 (c) 1 3 4 2 Incident ray 17. 70º SAMPLE PAPER 2 AO B Principal axis From the given figure, the refracted ray would travel (a) along OB (b) along OA (c) undeviated (d) at 20° to the direction of OB 18. A child knows that white light is coming from Sun but the sunlight that reaches Earth is yellowish rather than white. This is due to scattering and sunlight becomes deficient in (a) violet colour (b) blue colour (c) red and violet colours (d) violet, indigo and blue colours

CBSE Sample Paper Science Class X (Term I) 87 19. A ray of light travels from medium I to medium II. The figure shows the variation of sine of angle of incidence in medium I with sine of angle of refraction in medium II. Some conclusions are drawn as follows : sin r q>45° sin i I. Speed of light in medium I > Speed of light in medium II II. Speed of light in medium I < Speed of light in medium II III. Light travels from denser to rarer medium Which of the following statement(s) is/are correct? (a) Only I (b) Only II (c) I and III (d) II and III 20. fO f f/2 Examine the above figure and find the distance of image from lens. (a) f distance from left of lens (b) f distance from right of lens (c) 3 f distance from left of lens (d) 3 f distance from right of lens 2 2 21. Which one of the following statement is correct about the refraction of light through a glass prism? (a) Incident ray bend towards the base but the emergent ray bends away from base of prism. (b) Both incident and emergent rays bend towards the base. (c) Both incident and emergent rays bend parallel to the base. (d) Incident ray bends away from the base while emergent ray bend towards the base of prism. 22. Glass of 40° window pane Figure shows a ray of light meeting the glass of the window of a car at an angle of SAMPLE PAPER 2 incidence of 40°. Complete ray diagram is (a) (b) (c) 40º (d) Glass of Glass of Glass of Glass of window pane window pane window pane window pane

88 CBSE Sample Paper Science Class X (Term I) 23. If we use a concave mirror of focal length 2.5 cm as a dentist’s mirror, the distance of tooth from the mirror should be (a) less than 2.5 cm than the focal length (b) more than 2.5 cm than the focal length (c) less than 5 cm than the focal length (d) more than 5 cm than the focal length 24. 2f2 f1 O f1 2f2 From the given figure, the image should be (a) magnified and virtual (b) magnified and real (c) diminished and virtual (d) diminished, real and inverted Section B This section consists of 24 multiple choice questions with overall choice to attempt any 20 questions. In case more than desirable number of questions are attempted, ONLY first 20 will be considered for evaluation. + ¾¾® X Step II 25. + H 2O ¾¾® Glucose O2 Step I H 2 CO 3 Identify the correct option from the given table which represents the type of reaction in step I and acidic nature of H 2CO 3 in step II. Exothermic Acidic nature (a) û ü (b) ü û (c) ü ü (d) û û 26. In which year, the concentration of hydrogen ion is the highest? SAMPLE PAPER 2 6 2008 2012 2016 2020 5 Soil pH value pH 4 value 3 2 1 0 (a) 2008 (b) 2012 (c) 2016 (d) 2020

CBSE Sample Paper Science Class X (Term I) 89 27. The diagram shows the reaction between metal and dilute. acid. Zn+ Ag+ Dil.HNO3 Dil.HNO3 (A) (B) Cu+ Mg+ Dil.HNO3 Dil.HNO3 (C) (D) Which of the following statement is incorrect regarding the reactions taking place in four given test tubes? (a) In test tube A, nitrous oxide is evolved (b) In test tube B, nitrogen dioxide is evolved (c) In test tube C, nitric oxide is evolved (d) In test tube D, nitrogen dioxide is not evolved 28. The table shown below gives information about six elements A to F. Electronic configuration Formula of compound I. A : 2, 1 B : 2, 6 A2 B II. B : 2, 6 C : 2, 7 B 2C III. C : 2, 7 D : 2, 8, 3 DC 3 IV. E : 2, 8, 6 F : 2, 8, 8, 2 FE 3 Identify the compound which is wrongly formed. (a) I and II (b) II and IV (c) III and IV (d) I and III 29. Raj observed that after the reaction between hydrochloric acid and sodium hydroxide, sodium chloride and water are formed. Then, he searched about sodium chloride. Some of his statements about NaCl salt are given below : I. It is also prepared by chlor-alkali process. SAMPLE PAPER 2 II. It is a neutral salt, having pH value = 7. III. It is white crystalline solid. IV. It is also called rock salt. Select the correct statement(s). (b) II, III and IV (a) I, II and IV (d) III and IV (c) II and III

90 CBSE Sample Paper Science Class X (Term I) 30. On adding few drops of universal indicator to four colourless solutions, A, B, C and D having pH 2, 10, 9 and 7 respectively. Which of the following test tube is labelled with correct colour? Red Green Blue Violet (A) (B) (C) (D) (a) A and B (b) B and D (c) A, B and C (d) A and C Direction (Q. No. 31 to 34) Consist of two statements – Assertion and Reason. Answer these questions selecting the appropriate option given below : (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true, but R is not the correct explanation of A. (c) A is true, but R is false. (d) A is false, but R is true. 31. Assertion Plaster of Paris is used by doctors for setting fractured bones. Reason When plaster of Paris is mixed with water, it forms hard material called gypsum to support fractured bones. 32. Assertion Refrigeration of cooked food takes place at low temperatures. Reason To cool down the cooked food quickly. 33. Assertion All the veins carry deoxygenated blood from various organs to the heart. Reason Pulmonary artery carry deoxygented blood from the heart to the lungs. 34. Assertion In diffused reflection, a parallel beam of incident light is reflected in different directions. Reason The diffused reflection is due to the failure of laws of reflection. 35. The table given below provides information related to the reaction of a few compounds with hydrochloric acid and evolution of CO 2 in corresponding reaction. Compounds Reactivity with HCl Evolution of CO2 I. Na2CO3 üü II. ZnO üû SAMPLE PAPER 2 III. KOH ûû IV. AgNO3 üû Which of the following is incorrect option? (a) I and IV (b) I, II and III (c) II and III (d) Only III 36. Which one of the following juices secreted in the human body does not contain any enzyme? (a) Salivary juice (b) Bile juice (c) Gastric juice (d) Pancreatic juice

CBSE Sample Paper Science Class X (Term I) 91 37. Which type of respiration and reaction will take place in the germinating seeds in the experimental setup showing CO2 is evolved during respiration? (a) In anaerobic respiration, reaction is C6H12O6 + 6O2 ¾® 6CO2 + 6H2O + Energy (b) In aerobic respiration, reaction is C6H12O6 + 6O6 ¾® 2C2H2OH + 2CO2 + Energy (c) respiration in the presence of oxygen No Reaction (d) In aerobic respiration, reaction is C6H12O6 + 6O2 ¾® 6CO2 + 6H2O + Energy 38. If trypsin is lacking in the pancreatic juices, which of the following events in the small intestine will not takes place properly? (a) Starch breaking down into sugars (b) Absorption of vitamins (c) Digestion of proteins (d) Emulsification of fats 39. An object is placed 25 cm in front of a concave lens of focal length 25 cm. Find the location and nature of image. (a) At 5 cm from lens and real (b) At 12.5 cm from lens and virtual (c) At - 0.5 cm from lens and erect (d) At -12.5 cm from lens and diminished 40. P=8 D P=–10 D Find the power of combination of given lenses. (a) 18 D (b) 2 D (c) - 2 D (d) -18 D 41. Which of the following is protein digesting enzymes? (a) Trypsin, Amylase, Pepsin (b) Lipase, Trypsin, Amylase (c) Pepsin, Trypsin, Bile (d) Trypsin, Pepsin, Chymotrypsin 42. If Henle’s loop were absent from mammalian nephron, which one of the following to SAMPLE PAPER 2 be expected? (a) There will be no urine formation (b) There will be hardly any change in the quality and quantity of urine formed (c) The urine will be more concentrated (d) The urine will be more dilute 43. The refractive index of a dense flint glass and for alcohol are 1.65 and 1.36 respectively with respect to air. Then, the refractive index of dense flint glass with respect to alcohol will be (a) 1.10 (b) 1.21 (c) 1.31 (d) 1.5 44. A light ray is incident on a rectangular glass slab at an angle of 60°. The angle between the ray coming out of the slab and the normal to the face of rectangular slab from where it comes out is (a) 30° (b) 60° (c) 90° (d) 0°

92 CBSE Sample Paper Science Class X (Term I) 45. AB D CF 10 cm A square wire of side 1 cm is placed in front of concave mirror with one end at the centre of curvature as shown. Find the length of image of side CD. (a) 10 cm (b) 11 cm (c) 5 cm (d) 6 cm 11 10 6 5 46. At what distance, an object should be placed in front of a concave mirror of focal length 20 cm to get an erect image? (a) 10 cm (b) 20 cm (c) 25 cm (d) 40 cm 47. A A QR PS CB In the above diagram, light is travelling through different media. It is noticed by a scientist that ray QR is parallel to base CB. Which is the following statement would be correct? (a) Angle of deviation is minimum, (b) Angle of deviation and angle of prism are equal to angle of incidence. (c) Angle of emergence and angle of deviation are equal to angle of incidence. (d) Angle of deviation is maximum and equal to angle of incidence. 48. A jewellery making unit tested few elements on the basis of their physical properties. Properties A B C D Malleable Yes No No Yes Ductile Yes No No Yes Lustre Yes No Yes No Melting point High Low Low High Which of the above elements were discarded for usage by the company? (a) A, B and D (b) B, C and D (c) A and C (d) B and C SAMPLE PAPER 2 Section C This Section C consists of three Cases followed by questions. There are a total of 12 questions in this section. Attempt any 10 questions from this section. The first attempted 10 questions would be evaluated. Case I. The sample of acetic acid is taken in a clean test tube. Now, a blue litmus paper strip is taken and a drop of acetic acid is placed on litmus paper and the colour change is observed. Glass rod Drop of acetic acid pH paper

CBSE Sample Paper Science Class X (Term I) 93 Another test tube is taken and 1 mL of acetic acid is added into it. A pinch of sodium bicarbonate (NaHCO3 ) is added to test tube containing acetic acid. Pass the evolved gas through the lime water and observe the changes. Lime water Acetic acid Sodium bicarbonate 49. What is the effect on litmus paper after putting a drop of acetic acid? (a) Blue litmus paper turns red (b) Red litmus paper turns blue (c) Green colour is observed (d) No change in any litmus paper 50. The odour of the acetic acid taken in test tube is (a) sweet and fruity (b) like rotten egg (c) pungent (d) unpleasant 51. Complete the reaction involves in second experiment, CH 3COOH(aq) + NaHCO 3 (s) ¾® ? (a) CH3COONa, H2O (b) CH3COONa, H2O, CO2 (c) CH4 , CO2, NaOH (d) CH3OH, CO2, NaOH 52. What happens when excess of evolved gas is passed through lime water in experiment II? (a) The solution becomes more milky (b) The solution becomes yellow (c) The solution becomes transparent (d) No effect observed in solution Case II. In a given activity, freshly prepared lime water was taken in two test tubes marked A and B. Air is blown through mouth in lime water in test tube B. In test tube A, syringe or pichkari is used to pass air through the fresh lime water. Pichkari Rubber Tube tube Lime water Test tube containing lime water AB SAMPLE PAPER 2 I. Air being passed into limewater with a pickhari/syringe. II. Air being exhaled into limewater. 53. When air is blown from the mouth into a test tube containing limewater, the limewater turns milky due to the presence of (a) oxygen (b) carbon dioxide (c) nitrogen (d) water vapour 54. Limewater turns milky due to the formation of (a) water vapour (b) carbon dioxide (c) calcium carbonate (d) lactic acid