Arihant Science Class 10 Term 1 Sample Paper

194 CBSE Sample Paper Science Class X (Term I) Metal Gas evolved (i) Mg Yes (ii) Zn No (iii) Mn Yes (iv) Ca No (a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iii) (d) (iii) and (iv) 4. Which of the following is combination reaction ? (a) MgO + H2O ¾® Mg(OH)2 (b) Zn + FeSO4 ¾® ZnSO4 + Fe (c) Pb + CuCl2 ¾® PbCl2 + Cu (d) 2H2O ¾® 2H2 + O2 5. The graph given below depicts pH value of different chemicals. 14 B D 12 A 10 pH 8 C 6 4 2 0 Chemicals Which of the following produces the least number of hydrogen ions in a solutions? (a) A (b) B (c) C (d) D 6. In the given reaction, Na + Cl ¾® NaCl Which option in the given table correctly represents the cation and the anion? Cation Anion Cl- (a) Na+ Na+ (b) Cl- (c) Na- Cl+ Na- (d) Cl+ 7. The reaction between the outer surface of metal with air, water and chemicals present in the atmosphere can be categorised as SAMPLE PAPER 8 (a) reduction (b) combination (c) oxidation (d) decomposition 8. Which of the given options correctly represents the parent acid and the parent base of common salt? Parent acid Parent base (a) HCl NaOH (b) H2CO3 Ca(OH)2 (c) H3PO3 CaSO4 (d) H2SO4 NaOH

CBSE Sample Paper Science Class X (Term I) 195 9. Which indicator should be used to judge how strong a given acid or base ? (a) Olfactory indicators (b) Synthetic indicators (c) Natural indicators (d) Universal indicators 10. The silver chloride is kept in dark bottles because (a) it will evaporates (b) it’s colour will change to brown (c) it will decompose by sunlight (d) it will undergoes redox reaction 11. Carefully study the diagram of human circulatory system with labels (i) to (iv). Select the option which gives correct identification and main function and/or characteristic. Lung capillaries Pulmonary (i) Pulmonary artery to vein from lungs lungs (iv) (iii) (ii) Capillaries in body organs SAMPLE PAPER 8 apart from the lungs (a) (i) Pulmonary circulation — It is the blood circulation pathway in which deoxygenated blood from the body is sent directly to the lungs. (b) (ii) Systemic circulation — It is the circulation of blood in which oxygenated blood is pumped from heart to the body and deoxygenated blood is returned back to the heart. (c) (iii) Aorta — Carry deoxygenated blood from body to the lungs. (d) (iv) Vena cava — Carry deoxygenated blood from the lungs to the heart. 12. A plant is kept in the dark for two days. A leaf is used in an experiment to investigate the effect of two factors on photosynthesis as shown in the diagram. Cork cut so leaf can pass through Green Leaf removed and Q leaf tested for starch R Exposed Substance to absorb to light for carbon dioxide 8 hours

196 CBSE Sample Paper Science Class X (Term I) What are the colour of Q and R, when the leaf is tested for starch, using iodine solution? (a) Q-Blue/black R-Brown (b) Q-Brown R-Brown (c) Q-Blue/black R-Blue/black (d) Q-Brown R-Blue/black 13. Which of the following part of the human excretory system is under nervous control? (a) Ureters (b) Urethra (c) Urinary bladder (d) Kidneys 14. The figure given below shows the human digestive system with labels (i) to (iv). Identify the correct label with its function (i) (ii) (iv) (iii) (a) (i)-Salivary glands - They secrete pepsin for the digestion of starch. (b) (ii)-Pancreas - It secretes gastric juices in the small intestine. (c) (iii)-Gall bladder - It stores the bile. (d) (iv)-Liver - It secretes lipase that helps, emulsification of fat. 15. Identify the phase of circulation which is represented in the diagram of heart given below. Arrows indicate contraction of the chamber shown. SAMPLE PAPER 8 (a) Blood transferred to right ventricle and left ventricle simultaneously. (b) Blood is transferred to lungs for oxygenation and is pumped into various organs. (c) Blood transferred to right ventricle and right auricle simultaneously. (d) Blood comes from body organs and is pumped into the lungs.

CBSE Sample Paper Science Class X (Term I) 197 16. Observe the diagram of different stages of nutrition in Amoeba. Nucleus Food particle (A) (B) Pseudopodia Food vacuole Food particle (C) (D) Different stages of nutrition in Amoeba Match the labelling referred in Column I and correlate it with the Column II. Column I Column II A 1. During this process, the undigested food is thrown out of the body. B. 2. It is the procces by which Amoeba takes food with the help of finger-like projections. C. 3. During this process, complex substances are broken down into simple ones by digestive enzymes. D. 4. In this process, the digested food present in the food vacoule diffuses into the cytoplasm. Codes AB C D (a) 3 2 4 1 (b) 1 4 3 2 (c) 2 3 1 4 (d) 2 3 4 1 17. A ray of light falls normally or perpendicularly on the surface of a mirror. Which of the SAMPLE PAPER 8 following is not true regarding this? (a) The angle of incidence for such a ray of light is zero. (b) The angle of reflection for such a ray of light is zero. (c) This ray is reflected back along the same path. (d) The ray of light does not follow law of reflection. 18. The magnification produced by a convex mirror is always (a) equal to unity (b) less than unity (c) greater than unity (d) equal to -1

198 CBSE Sample Paper Science Class X (Term I) 19. A ray of light is incident on concave lens as shown P Principal axis 70º B A O Concave lens Then, the refracted ray would travel (b) along OA (a) along OB (d) at 20° to the direction of OB (c) undeviated 20. In an experiment to trace the path of a ray of light passing through a rectangular glass slab, the correct markings of angle of incidence (i), angle of refraction (r) and angle of emergence (e) is shown below in which diagram? i i i i (b) r (c) r r r (a ) (d ) e ee e 21. The angle of refraction at point P on the hemispherical flint glass slab is A Air 60° O Flint glass Air P B (a) 180° (b) 45° (c) 90° (d) 0° 22. Refractive indices of glass for violet, yellow and red colours are m v , m y and m r , respectively. Arrange these in correct order of their values. (a) mr < my < mv (b) m y < m r < m v (c) m v < m y < m r (d) m r < m y > m v 23. The line PQ in the ray diagram as shown, represents which optical device? P SAMPLE PAPER 8 (a) Convex lens Q (c) Convex mirror (b) Concave mirror (d) Concave lens

CBSE Sample Paper Science Class X (Term I) 199 24. Radha has to do an experiment on determining the focal length of a given concave mirror by using a distant object. Out of the following set ups available to her, the set up that is likely to give her the best result is (a) a mirror holder, a screen holder and a scale (b) a screen, a mirror holder and a scale (c) a screen holder and a scale (d) a mirror holder and a screen holder 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. Two reactions are given below? Reaction A : CH4 (g) + 2O2(g) ¾® CO2 (g) + 2H2O(g) + Heat Methane Oxygen Carbon dioxide Water Reaction B : 6CO2(aq) + 12H2O(l) ¾S¾unli¾g¾ht ® C 6H 12O6 + 6O2 + 6H 2O Chlorophyll Glucose Identify the correct option from the given table which represents the type of reactions occurring in reaction A and B respectively? Exothermic Endothermic (a) 3 3 (b) O 3 (c) 3 O (d) O O 26. Salman collected four samples of water from four different water bodies of his village. He recorded the pH value of different sample as 14 A BCD 12 10 pH 8 6 4 2 0 Which water body have pH value similar to distilled water? (a) A (b) B (c) C (d) D 27. A student performed the following four experiments. FeSO4(aq) FeSO4(aq) FeSO4(aq) FeSO4(aq) SAMPLE PAPER 8 Al Zn Fe Cu I II III IV Which of the following observation is correct? (a) The displacement reaction occurs in all experiments except III (b) The solid deposition is observed in I, II and III experiments (c) The solid deposition is observed in I and II experiment (d) The displacement reaction is observed in IV experiment

200 CBSE Sample Paper Science Class X (Term I) 28. The table shown below have elements with their electronic configuration. Elements Electronic configuration A 2, 8, 1 B 2, 8, 2 C 2, 8, 7 D 2, 8, 5 Identify the elements that form an ionic compound from the above given substances. (a) A, B (b) B, C (c) A, B, D (d) A, C 29. Seerat observed that when washing soda is scrubbed on the stain of curry, the stain becomes reddish-brown. But when it is washed with lemon juice it becomes yellow again. What might be the reason for our observation? I. Washing soda is basic in nature. II. Washing soda is acidic in nature. III. Turmeric gives reddish tinge in bases. IV. Turmeric gives reddish tinge in acids. (a) I and II (b) I and III (c) II and III (d) III and IV 30. A metal rod (A) was dipped in coloured solution (B). After sometime, it was observed that the metal rod starts dissolving in the solution and the solution starts fading its colour. A coloured precipitate (C) was seen at bottom of beaker. Identify (A), (B) and (C). A B C (a) A = Zn, B = FeSO4, C = Fe (b) A = Cu, B = Al 2(SO4 )3, C = Al (c) A = Ag, B = CuSO4 , C = Cu (d) A = Fe, B = ZnSO4, C = Zn 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. SAMPLE PAPER 8 (d) A is false, but R is true. 31. Assertion Food materials are often packed in air-tight container. Reason The oxidation of fats and oils of food material leads to rancidity. 32. Assertion Tooth decay starts when the pH of mouth is lower than 5.5. Reason The bacteria present in the mouth produce acids on reacting with food that remains in the mouth after eating cause tooth decay. 33. Assertion Plant can survive without separate respiratory organs. Reason Each part of plant takes care of its own gas exchange needs.

CBSE Sample Paper Science Class X (Term I) 201 34. Assertion Higher the refractive index of prism material, lower is the angle of deviation. Reason The angle of deviation is inversely proportional to the angle of prism. 35. The table given below shows the reaction of a few metals with different salt solution. Element CuSO4 FeSO4 ZnSO4 Zn 3 3 O Cu O O O Al 3 3 3 On the basis of above data, the order of the reactivity of metal is (a) Zn > Al > Cu (b) Al > Cu > Zn (c) Cu > Zn > Al (d) Al > Zn > Cu 36. The correct path of lymph flow is (a) lymphatic capillaries ® lymph vessels ® veins (b) lymphatic, capillaries ® lymph vessels ® arteries (c) veins ® lymph vessels ® lymphatic capillaries (d) arteries ® lymph vessels ® lymphatic capillaries 37. Root pressure is maximum when (a) transpiration is very low and absorption is very high (b) transpiration is very high and absorption is very low (c) Both transpiration and absorption are very high (d) Both transpiration and absorption are very low 38. Which of the following equation is the summary of photosynthesis? (a) 6CO2 + 12 H2O ¾® C6H12O6 + 6O2 + 6H2O (b) 6CO2 + H2O + Sunlight ¾® C6H12O6 + O2 + 6H2O (c) 6CO2 + 12 H2O + Chlorophyll + Sunlight ¾® C6H12O6 + 6O2 + 6H2O (d) 6CO2 + 12H2O + Chlorophyll + Sunlight ¾® C6H12O6 + 6CO2 + 6H2O 39. If the focal length of concave lens is - 50 cm, then it means the lens has a (a) power of - 2 D (b) power of + 0.02 D (c) power of + 2 D (d) power of - 0.02 D 40. The image formed by a concave mirror of focal length 15 cm is observed to be virtual, erect and larger than the object. Where should be the position of the object? (a) More than 30 cm in front of the mirror (b) 30 cm in front of the mirror (c) Less than 15 cm in front of the mirror (d) Between 15 cm and 30 cm in front of the mirror 41. Name the two ways in which glucose is oxidised to provide energy in various SAMPLE PAPER 8 organisms. (a) Aerobic respiration and anaerobic respiration (b) Respiration and breathing (c) Fermentation and breathing (d) None of the above 42. Which of the following events will be affected if bile juice is not secreted? (a) Activation of pancreatic enzyme (b) Breaking down of starch (c) Breaking down of protein molecules (d) Activation of gastric enzyme

202 CBSE Sample Paper Science Class X (Term I) 43. The refractive index of glass w.r.t. air is 3 and that of diamond w.r.t. air is 12. The 25 refractive index of glass relative to diamond will be (a) 5 (b) 1 (c) 5 (d) 5 2 4 8 18 44. 2F F Screen Suhani covered one-half of a convex lens with a black paper and observed the following I. This lens produces a complete image of the object. II. The image forms on same side of object. III. Brightness of the image decreases IV. Image formation depends upon the size of a lens. Which one of the above statements are incorrect? (a) (I) and (III) (b) (II) and (III) (c) (II) and (IV) (d) (I) and (IV) 45. In the following diagram, light is travelling through different media. It is noted by a scientist that Ð i for both cases is same but Ð r is different. 30º 30º Air Air Medium 2 Medium 1 45º 10º Which of the following statement would be correct? (a) Medium 1 is denser than medium 2. (b) Medium 2 is the rarest medium. (c) Medium 1 and medium 2 are essentially same medium. (d) Medium 1 is the rarest medium. 46. Mohit performed the glass slab experiment using different angles of incidences. He measured the angle of refraction and emergence in each case and recorded them as given in the table. SAMPLE PAPER 8 S.No. Angle of incidence Angle of refraction Angle of emergence (Ðe) (Ði) (Ðr) 30° 1 30° 25° 40° 2 40° 45° 54° 64° 3 50° 52° 4 60° 58° Which of the observation made by him is correct? (a) 1 (b) 2 (c) 3 (d) 4

CBSE Sample Paper Science Class X (Term I) 203 47. The focal length of above lens is 10 cm. Find the location of image. Object O 10 cm (a) 10 m from right of lens (b) 5 cm from left of lens (c) 5 cm from right of lens (d) 10 cm from left of lens 48. Four metals, A, B, C and D are reacted with dilute sulphuric acid and water. The table given below shows the result of experiment. Elements Reaction with dil. H2 SO4 Reaction with water A 3 7 B 3 7 C 3 3 D 7 7 Among four metals, which is the most reactive element? (a) A (b) B (c) C (d) D 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. All metals do not react with water as the metals placed lower in the reactivity series are less reacting towards water. A group of students performed an experiment based on reactivity of metal and gas evolved. An experimental set up is shown in the figure. The metal X is used in the given experimental setup which evolves gas Y in glass jar. Metal X Gas Y Glass wool Water slaked Gas jar with water Burner 49. Identify the metal (X) in this experiment. SAMPLE PAPER 8 (a) Zinc (b) Copper (c) Aluminium (d) Platinum 50. Identify the gas evolved (Y) in this experiment. (a) CO2 (b) H2 (c) O2 (d) H2S 51. Which one of the following metal reacts most vigorously with cold water? (a) Sodium (b) Magnesium (c) Copper (d) Zinc

204 CBSE Sample Paper Science Class X (Term I) 52. Which of the following does not react with water? (a) Silver (b) Gold (c) Lead (d) All of these Case II. Ram was complaining for the dizziness. So, doctor measured Ram’s blood pressure. Doctor used the given instrument for checking and said that it is not normal. Ram readings came out to be 150/100 mm Hg. He precribed certain medicines to get it back to the normal. Rubber cuff A Sounds inflated audible in with air Artery stethoscope closed Artery Sounds stop 53. The device (A) used to measure BP is (b) pulse recorder (d) thermometer (a) electrocardiograph (c) sphygmomanometer 54. Which of the following reason for low blood pressure? (a) Constriction of ventricles (b) Relaxation of ventricles (c) Relaxation of arterioles (d) Constriction of arterioles 55. The doctor measured Ram’s blood pressure again after medication and said it is normal now. The range of Ram’s blood pressure is likely to be (a) the systolic pressure is 120 mm Hg and the diastolic is 80 mm Hg (b) the systolic pressure is 80 mm Hg and the diastolic is 120 mm Hg (c) the systolic pressure is 160 mm Hg and diastolic is 80 mm Hg (d) the systolic pressure is 180 mm Hg and diastolic is 100 mm Hg 56. Which of the following caused by hypertension? I. Rupture of an artery II. Internal bleeding III. Increase resistance to blood flow IV. Rupture of veins (a) I and II (b) I, II and III (c) III and IV (d) I and III Case III. Shefali set up an experiment arrangement shown, S is a strong source of white light and L1 is a convex lens. Distance between S and L1 is equal to focal length of lens L1. So, after refraction through L1, the light beam becomes a parallel beam of light. This light beam passes through a transparent glass tank T containing clear water. Emergent beam of light passes through a circular, hole C made in a cardboard sheet. A convex lens L2 forms a sharp image of the circular hole on a SAMPLE PAPER 8 screen MN. M L2 L1 C S f1 T f2 N Then, she added 200 g of sodium thiosulphate and 1-2 mL of concentrated sulphuric acid to the water.

CBSE Sample Paper Science Class X (Term I) 205 57. After adding the hypo and concentrated sulphuric acid to the water tank, she observes (a) colour of solution becomes black (b) solution becomes milky white (c) precipitate will form at bottom of tank (d) solution becomes colloidal 58. The phenomenon involved in this experiment is (a) dispersion of light (b) scattering of light (c) refraction of light (d) recombination of light 59. Her friend noted some observations about this demonstration as follows I. Colour of solution becomes bluish. II. Light is transmitted from the front side of the glass tank facing circular hole . III. An orange-red spot appears on the screen MN. IV. After sometime, a bright crimson red colour spots on the screen. Which one of the above combinations of statements is correct? (a) I and III (b) III and IV (c) II, III and IV (d) I, II, III and IV 60. Near horizon, the sun appears orange as (a) all the shorter wavelengths are scattered away (b) red light gets scattered and reaches the eye of observer (c) all colours of white light get scattered in all directions (d) light travels shorter distance relatively SAMPLE PAPER 8

OMR SHEET SP 8 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) 207 Answers 1. (b) 2. (a) 3. (c) 4. (a) 5. (d) 6. (a) 7. (c) 8. (a) 9. (d) 10. (c) 11. (b) 12. (b) 13. (c) 14. (c) 15. (a) 16. (d) 17. (d) 18. (b) 19. (c) 20. (c) 21. (d) 22. (a) 23. (a) 24. (b) 25. (a) 26. (b) 27. (c) 28. (d) 29. (b) 30. (a) 31. (a) 32. (a) 33. (a) 34. (d) 35. (d) 36. (a) 37. (a) 38. (c) 39. (a) 40. (c) 41. (a) 42. (a) 43. (c) 44. (c) 45. (d) 46. (a) 47. (b) 48. (c) 49. (a) 50. (b) 51. (a) 52. (d) 53. (c) 54. (a) 55. (a) 56. (b) 57. (d) 58. (b) 59. (d) 60. (a) EXPLANATIONS 1. CuSO4 + 2 NH4OH ¾® Cu(OH)2 + (NH4 )2 SO4 oxygen to form metal oxide which is known as rust in case of iron. Copper Ammonium (Pale blue) Ammonium sulphate hydroxide (Copper hydroxide) sulphate 8. NaCl is also known as common salt. It is The reaction between copper sulphate and formed by the reaction between strong acid ammonium hydroxide produces pale blue precipitate of copper hydroxide along with HCl and strong base NaOH. ammonium sulphate. NaOH + HCl ¾® NaCl + H2O 2. Vinegar (acetic acid) is an edible acid. It’s pH value is around 2.5. (Strong (Strong (Neutral (Water) 3. When a metal reacts with dil. HNO3, hydrogen base) acid) salt) gas (H2) is evolved along with the salt of metal. Mg + dil. HNO3 ¾® Mg(NO3 )2 + H2 ­ 9. Universal indicator is a mixture of several indicators. It shows different colours at different (Gas) concentrations of hydrogen ions in a solution. Hence, it is most suitable to judge how strong a Zn + dil. HNO3 ¾® Zn(NO3 )2 + H2 ­ given acid or base is because it gives different Mn + dil. HNO3 ¾® Mn(NO3 )2 + H2 ­ colours in different concentration of acid and Ca + dil. HNO3 ¾® Ca(NO3 )2 + H2 ­ base. 4. A reaction in which two or more reactants 10. Silver chloride undergoes decomposition in combine to form a single product is called sunlight. Hence, it is kept in dark bottles. combination reaction. e.g. MgO + H2O ¾® Mg(OH)2 11. (ii) Systematic circulation is the type of Reaction (b) and (c) are displacement reaction circulation of blood in which oxygenated whereas reaction (d) is decomposition reaction. blood is pumped from heart to the body and deoxygenated blood is returned back to 5. The pH value of chemical D is highest among the heart. the others. Its pH value is 10 which means it is basic in nature. Incorrect options can be corrected as : Hence, produces the least number of H+ ions in a solution. (i) Pulmonary circulation - It is a blood circulation pathway that moves blood 6. Metals have a tendency to loose electrons to between heart and lungs. form cations (+ ve ions) and non-metals have a tendency to gain electrons to form anions (-ve (iii) Aorta - Carries oxygenated blood from SAMPLE PAPER 8 ions). heart to body. In case of NaCl, Na+ acts as cation and Cl- acts as anion. (iv) Vena cava - Carries deoxygenated blood from body to the heart. 7. The phenomenon due to which open surface of the metals are slowly eaten away by the 12. For photosynthesis to occur, both sunlight and reaction of air, water and chemicals present in the atmosphere, is called corrosion. It is a type CO2 are required. The part Q of leaf was of oxidation reaction as metal reacts with covered and not exposed to light and part R was kept in the absence of CO2. Thus, both parts of leaf did not form starch and gave a negative test for starch. (Note-Iodine solution gives a positive test for starch and turns blue-black in colour). Thus, during starch test with iodine both Q and R turns brown and not as blue-black. Both the regions lack starch.

208 CBSE Sample Paper Science Class X (Term I) 13. The urinary bladder is a muscular structure is the angle between the emergent ray and the that stores the urine until we get the urge to normal at glass-air interface as shown below urinate. It is under nervous control. Incident Normal 1 14. (iii) The gall bladder functions as a ray i concentrating reservoir for bile, which it delivers to the duodenum. Air Incorrect options can be corrected as Glass r Refracted (i) Salivary glands - They secrete salivary amylase for the digestion of starch. ray (ii) Pancreas - It secretes pancreatic juice in the Glass e Emergent small intestine. Air Normal 2 ray (iv) Liver - It secretes bile juice that acts on large 21. The ray of light passes radially outward from fat molecules to form smaller globules. the surface of hemispherical flint glass slab, so the angle of incidence and angle of refraction 15. Right and left auricle contracts at the same time, at the point P is 0°. pumping blood to the right and left ventricles. 22. As we know, wavelength of red is more than Incorrect statements can be corrected as yellow and violet. l Blood is transferred to lungs for oxygenation and is sent back to heart for transportation to Refractive index µ 1 body parts. Wavelength l Blood transferred to left and right auricle simultaneously. \\ lv < ly < lr Þmr < my < mv l Blood comes from body organ and enters the 23. The optical device represented by line PQ is heart. convex lens because the rays become less divergent after refraction through the lens. 16. A. Ingestion Amoeba ingests food particle by forming temporary finger-like projections 24. Radha requires a screen, a mirror holder and a called pseudopodia around it. The food is scale to determine the focal length of a given engulfed forming a food vacuole. concave mirror by using a distant object. B. Digestion Inside the food vacuole, 25. In reaction A, energy is produced in form of complex substances are broken down into heat. Hence, it is an exothermic reaction. simpler ones by digestive enzymes. CH4 + 2O2 ¾® CO2 + 2H2O + Heat C. Absorption The digested food present in In reaction B, energy is absorbed in form of the food vacuole diffuses into the cytoplasm. sunlight. Hence, it is an endothermic reaction. D. Egestion The remaining undigested 6CO2(aq) + 12H2O(l) ¾S¾unli¾ght ® C 6H12O6 + 6O2 material moves to the surface of the cell, Glucose + 6H2O the cell membrane ruptures at any place Chlorophyll and undigested food is thrown out of the body. 26. The pH of water body B is 7 and the pH of normal distilled water is also 7. Therefore, 17. When a ray of light falls normally, the angle of option (b) is correct. incidence and reflection both are zero and light ray is reflected back along the same path by 27. In experiments I and II, there is solid deposition following law of reflection. because Al and Zn are more reactive than Fe and in experiment IV, no reaction occur because, Fe 18. Images formed by convex mirror are always is more reactive than copper (Cu). diminished. So, magnification is always less SAMPLE PAPER 8 than unity or + 1. 28. Element A has 1 electron to transfer or loose and C can gain 1 electron fulfil its octet. So, A 19. When a ray of light is incident on optical transfer one electron to C and make ionic centre, it passes undeviated. compound. 20. The angle of incidence (i) is the angle between 29. Both I and III are correct. Turmeric is a natural the incident ray and the normal at the air-glass indicator which turns red on reacting with interface, the angle of refraction (r) is the angle base like washing soda and gives yellow between the refracted ray and the normal at colour on reaction with acid like lemon juice. air-glass interface and the angle of emergence 30. Zinc is more reactive than iron, so it can displace iron from its salt solution by undergoing displacement reaction and then

CBSE Sample Paper Science Class X (Term I) 209 iron will start depositing at the bottom of absorption is input of water into plant. If the output is low and input is high, the pressure will beaker. be greatest. Zn+ Fe SO4 ¾® ZnSO4 + Fe (A) (B) (C ) 38. The summary of photosynthesis is (A) Metal rod is zinc rod. 6CO2 + 12H2O + Chlorophyll + Sunlight ¾® C6H12O6 + 6H2O (B) Coloured solution is ferrous sulphate. Photosynthesis is a process by which green (C) Precipitate is iron. This experiment is based on displacement plants makes their own food by using CO2 and reaction. H2Oin the presence of sunlight and chlorophyll. 31. Both A and R are true and R is the correct 39. Given, f = - 50 cm explanation of A. \\Power, P = 100 Þ P = 100 = - 2 D The oxidation of food items which contain fats f (in cm) - 50 and oil is known as rancidity. It spoil food and changes its taste and smell. To prevent 40. To obtain virtual, erect and larger image of rancidity, food items are stored in air tight object from concave mirror, object is placed container. between the pole of the mirror and its principal focus. So, the image should be placed at a 32. Both A and R are true and R is the correct distance less than 15 cm from the mirror. explanation of A. 41. The two ways in which glucose is oxidised to Bacteria present in our mouth reacts with provide energy in various organisms is sugar and produce acid. This acid cause tooth through the aerobic (in the presence of oxygen) decay by decomposing our enamel of tooth. and anaerobic (in lack of oxygen) respiration. 33. Both A and R are true and R is the correct 42. Bile is digestive juice secreted by the liver. It explanation of A. plays an important role in the digestion of fats. It also makes the medium alkaline and activate Plants do not have specialised respiratory lipase. If bile juice is not secreted then activation organ. Each plant part takes care of its own gas of pancreatic enzymes will be affected. exchange needs through diffusion. 34. A is false , but R is true. 43. Given, a mg = 3 , am = 12 2 d 5 Higher the refractive index of the prism material, greater is the angle of deviation. \\ dmg = amg = 3 = 5 a md 2 8 The angle of deviation is inversely 12 proportional to the angle of prism. 35. According to reactivity series, 5 Al > Zn > Cu 44. When one-half of a convex lens is covered with a Al is more reactive than zinc and copper and Zn is more reactive than copper. The most black paper, this lens produces a complete reactive element (Al) shows all displacement image of the object but the brightness of the reaction involved in this experiment and least image decreases because some part of lens is reactive element (Cu) does not show any displacement reaction with given salt solution. blocked and also image formation does not depend upon the size of a lens. So, statements I and III are correct, while II and IV are incorrect. 36. Lymph flows only in one direction, that is from 45. As the angle of incidence for both the incident SAMPLE PAPER 8 tissues to heart. From the intercellular space, ray is same, but angle of refraction in medium 1 lymph drains into lymphatic capillaries, which is more than medium 2. So, medium 1 is the join to form large lymph vessels that finally rarest medium because light ray bends away open into large veins. from normal more in medium 1 than medium 2. The path of circulation of lymph is 46. In glass slab experiment, lymphatic capillaries ® lymph vessels ® veins Ði > Ðr and Ðe = Ði 37. Root pressure is the pressure that develops in So, observation 1 is correct. the roots of the plants by active absorption of nutrients from the soil. 47. Given, f = - 10 cm, u = - 10 cm Roots pressure is maximum when transpiration Using lens formula, is very low and absorption is high because transpiration is output of water from plant and 1-1= 1 vu f

210 CBSE Sample Paper Science Class X (Term I) Þ 1=1+ 1= 1 - 1 55. The normal systolic pressure is about 120 mm v u f - 10 10 of Hg and diastolic pressure is 80 mm of Hg. Þ 1 = - 2 = - 1 Þ v = - 5 cm 56. High blood pressure or hypertension is v 10 5 caused by the constriction of arterioles; which results in increased resistance to blood Hence, image is at 5 cm from left of lens. flow. 48. Since, C shows reaction with both dilute It can lead to the rupture of an artery and sulphuric acid and water, it is considered as internal bleeding. most reactive among others. 57. After adding the hypo and concentrated 49. Zinc do not react with cold or hot water but it sulphuric acid to the water tank, she reacts with steam. observes the solution becomes colloidal. Thus, metal X is zinc, whereas copper, 58. The phenomenon involved in this experiment aluminium and platinum do not react with is scattering of light by colloidal particles. water at all. 59. The colour of solution becomes bluish due to 50. H2 gas is evolved in this experiment. the scattering of wavelengths by minute colloidal sulphur particles. The colour Zn + H2O(g) ¾® ZnO + H2(g)­ transmitted light from the glass tank is at Zinc Steam Zinc oxide Hydrogen first the orange-red colour and then becomes bright crimson red colour on the 51. Sodium is the most reactive metal and it screen. vigorously reacts with cold water. 60. Near horizon, the Sun appears orange because all the shorter wavelengths are 52. Silver, gold and lead are least reactive metals as scattered away by the particles. Therefore, they present at the bottom of the reactivity the light reaches our eyes is of longer series. They do not react with water at all. wavelengths. This gives rise to the reddish or orange appearance of the Sun. 53. Blood pressure is measured with an instrument called sphygmomanometer. 54. Low blood pressure is caused by the constriction of ventricles. SAMPLE PAPER 8

SAMPLE PAPER 9 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. A student took 5 mL of potassium iodide and 5 mL of lead nitrate and mixed together. What would he observe ? (a) The solution become green (b) Yellow precipitate was formed (c) White precipitate was formed (d) The solution become hot 2. Identify the gas A in the following experiment. Gas A Boiling tube Red lead oxide Burner (a) H 2 (b) CO 2 (c) O 2 (d) H 2 O

212 CBSE Sample Paper Science Class X (Term I) 3. Metal Dil. H2SO4 Metal salt Gas Which of the following two combination are correct ? Metal Gas evolved (i) Zinc No (ii) Iron Yes (iii) Magnesium No (iv) Aluminium Yes (a) (i) and (iii) (b) (i) and (iii) (c) (ii) and (iii) (d) (ii) and (iv) 4. Which of the following represents correct balanced chemical equation? (a) KI(aq) + Pb(NO3 )2 (aq) ¾® 2KNO 3 (aq) + PbI 2 (s) (b) 2KI(aq) + Pb (NO 3 ) 2 (aq) ¾® 2KNO 3 (aq) + PbI 2 (s) (c) KI(aq) + Pb(NO 3 ) 2(aq) ¾® KNO 3 (aq) + PbI 2 (s) (d) 3KI(aq) + 2Pb(NO 3 ) 2 (aq) ¾® 3KNO 3(aq) + 2PbI 2 (s) 5. The graph given below depicts a neutralisation reaction. The pH of a solution changes as we add excess of sulphuric acid to sodium bicarbonate 14 A B 7 C pH D value O Volume of sulphuric acid added Which letter denotes the area of graph where both sulphuric acid and salt are present ? (a) A (b) B (c) C (d) D 6. In the reaction of aluminium with copper sulphate solution, SAMPLE PAPER 9 3CuSO4 + 2Al ¾® 3Cu + Al 2 (SO 4 ) 3 Which option in the given table correctly represents the substance oxidised and the reducing agent? Substance oxidised Reducing agent (a) Al Al (b) Al Al 2 (SO 4 ) 3 (c) Cu Al (d) CuSO 4 Al

CBSE Sample Paper Science Class X (Term I) 213 7. The chemical reaction between aluminium and oxygen can be categorised as (a) displacement reaction (b) decomposition reaction (c) combination reaction (d) double displacement reaction 8. Which of the given option correctly represents the parent acid and base of potassium carbonate? Parent acid Parent base (a) HCl KOH (b) H 2 CO 3 KOH (c) H 3 PO 4 (d) H 2 SO 4 KSO 4 KSO 4 9. Chloroform is stored in dark coloured bottles because (a) it gets oxidised to phosgene in presence of sunlight (b) it undergoes redox reaction (c) it undergoes combination reaction (d) it is white solid 10. Identify the chemical equation which have correct states of reactants and products. (a) 4Na(l) + O 2 (g) ¾® 2Na 2 O(s) (b) NaOH(s) + HNO 3(aq) ¾® NaNO 3 (s) + H 2 O(l) (c) 2KClO3 (s) ¾® 2KCl (s) + 3O 2 (g) (d) CuO(s) + H2 (g) ¾® Cu(l) + H 2 O(g) 11. Carefully study the diagram of the human digestive system with labels (i) to (iv). Select the option which gives correct identification and main function and/or characteristics. Tongue (i) Diaphragm Oesophagus (ii) Gall bladder (iv) (stores bile) Large intestine Bile duct (Colon) Liver (iii) Appendix Anus SAMPLE PAPER 9 (a) (i)-Buccal cavity – It consists of two major parts duodenum and jejunum (b) (ii)-Stomach – It consists of gastric glands which secrete HCl, mucus and pepsin (c) (iii)-Pancreas – It is present just in front of stomach and secretes bile (d) (iv)-Small intestine – It is the shortest part of the alimentary canal, which is site of carbohydrate’s digestion only.

214 CBSE Sample Paper Science Class X (Term I) 12. Identify the option that indicates the correct labelling for (i), (ii) and (iii). (ii) (iii) (i) (a) (i)-Right auricle, (ii) Aorta, (iii)-Pulmonary artery (b) (i)-Right auricle, (ii)-Pulmonary artery, (iii)-Pulmonary vein (c) (i)-Right auricle, (ii)-Pulmonary vein (iii)-Aorta (d) (i)-Right auricle, (ii)-Pulmonary vein, (iii)-Pulmonary artery 13. The blood leaving the tissues becomes richer in (a) oxygen (b) water (c) carbon dioxide (d) haemoglobin 14. The figure given below shows a human respiratory system with labels (i) to (iv). Identify the correct label with its function and/or characteristics. (i) (ii) (iii) SAMPLE PAPER 9 (iv) (a) (i)-Nasal passage – It serves as a passageway of air directly into alveoli. (b) (ii)-Cartilagenous rings – They are present in oesophagus and ensure it does not collapse (c) (iii)-Lungs – They facilitate the exchange of gases (d) (iv)-Alveoli – They are balloon-like structures lined with hair and mucus to filter the air from dust and dirt 15. Identify the phase which is represented in the diagram of the stomata given below. Guard cells Stomatal pore Chloroplast (a) The guard cell shrinks when water flows out of them causing stomatal pore to close (b) The guard cells swell when water flows into them, causing the stomatal pore to open (c) The guard cell shrinks when there is too much water loss, causes stomatal pore to remains open (d) The guard cells swell when water flows into them, causing the half opening and half closing of stomatal pore

CBSE Sample Paper Science Class X (Term I) 215 16. Observe the diagram of human excretory system. D BA C Match the labelling referred in Column I and correlate with the Column II. Column I Column II A 1. It is the temporary reservoir for the urine B 2. It carries unfiltered blood from heart to the kidneys C 3. They contain nephrons which are the filtering units D 4. They connect kidneys with the bladder Codes ABCD ABCD (b) 4 1 2 3 (d) 3 1 2 4 (a) 3 4 1 2 (c) 3 2 4 1 17. Name a liquid whose mass density is less than that of water but it is optically denser than water. (a) Kerosene (b) Liquid paraffin (c) Liquid glass (d) Mercury 18. A beam of monochromatic light is incident on the box through the holes A and B and emerges out of the box through P and Q respectively, as shown BA QP What is inside the box? (a) A convex lens (b) A concave lens SAMPLE PAPER 9 (c) A rectangular glass slab (d) A prism 19. In an experiment with a rectangular glass slab, a student observed that a ray of light incident at an angle of 55°, after refraction strikes the opposite face before emerging it makes an angle of 40° with normal. Which of the following is correct? (a) Angle of emergence is 50° (b) Angle of refraction is 40° (c) Ray goes from denser to rarer medium (d) Ði = Ðr = 55°

216 CBSE Sample Paper Science Class X (Term I) 20. Which one pair is wrongly matched in given columns ? Column I Column II (a) m = 1 Plane mirror (b) Real image Convex mirror (c) Power = -2 D Concave lens (d) Bottom of tank appears to be raised Refraction 21. S i2 B AR r2 r1 D Q i1 C P Examine the above figure. What is the net deviation suffered by the ray on passing the glass slab? (a) r1 - i1 (b) i2 - r2 (c) zero (d) i1 - r1 22. Choose the correct path of ray by convex lens from the following. (a) F2 (b) F2 F1 F1 (c) F2 (d) F2 F1 F1 23. How much time from sunrise to sunset is lengthened due to atmospheric refraction? (a) 4 hours (b) 2 minutes (c) 4 minutes (d) 2 hours 24. After tracing the path of the light through a glass prism, a student marked the angle of incidence (i), angle of refraction (r), angle of emergence (e) and angle of deviation (D) as shown in figure. The correctly marked angles are SAMPLE PAPER 9 i r e d (a) i and r (b) i, r and e (c) i and e (d) i, e and d

CBSE Sample Paper Science Class X (Term I) 217 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. Limestone ¾¾D ® CaO + X Identify the correct option from the given table which represents the type of reaction and gas evolved. Endothermic Gas evolved (a) ü û (b) û ü (c) ü ü (d) û û 26. In which year is concentration of hydrogen ion the lowest ? 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) 2006 (c) 2008 (d) 2011 27. The diagram shows the reaction between metal and dil. acid. Zn+ Mg+ Fe+ Ca+ dil.HCl dil.HCl dil.HCl dil.HCl A BC D Which of the following reaction is observed in the given experiment? (a) Displacement reaction (b) Combination reaction (c) Decomposition reaction (d) Double displacement reaction 28. The table shown below gives information about four substances P, Q, R and S Substance Melting Electrical conductivity SAMPLE PAPER 9 point (K) P Solid Aqueous Q 390 R 1310 Good Good S 1730 1160 Poor Good Poor Good Poor Poor Which of the following will form ionic compound ? (a) P and Q (b) Q and R (c) R and S (d) P and S

218 CBSE Sample Paper Science Class X (Term I) 29. Neeraj observed that the stain of curry on a white shirt becomes reddish-brown when baking soda 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. Baking soda is acidic in nature. II. Baking soda is basic in nature. III. Turmeric is 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 30. In which of the following setup 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 Glucose solution Rubber cork Rubber cork Bulb Bulb Switch Switch Beaker Beaker III. IV. Nail Nail Alcohol in water Lemon juice Rubber cork Rubber cork (a) (I) and (II) (b) (I) and (IV) (c) (II), (III) and (IV) (d) (I), (II) and (IV) SAMPLE PAPER 9 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 The elements which form acidic oxides are metals. Reason Metal oxides gives hydroxide ions in water. 32. Assertion The elements like carbon and sulphur do not react with dilute acids. Reason Non-metals donate electrons to hydrogen ion of acid.

CBSE Sample Paper Science Class X (Term I) 219 33. Assertion The starch solution in which saliva is added, do not turn blue or black on putting drops of iodine. Reason The enzyme present in saliva digest the starch. 34. Assertion As the temperature of a medium increases, the refractive index decreases. Reason When a ray travels from vacuum to a medium, then m is known as the absolute refractive index of medium. 35. The table given below shows the reaction of a few elements with HCl and NaOH to evolve hydrogen gas. Which of these elements can form amphoteric oxides ? Element HCl NaOH A ûû B üü C üû D üü (a) A and D (b) B and D (c) A and C (d) B and C 36. Waste products in plants are stored in the form of (a) tannins, carbohydrates, dry leaves (b) resins, urea, gums (c) tannins, essential oils, gums (d) nitrogen, dry leaves , carbon dioxide 37. Which one of the following statement is incorrect? (a) Organisms grow with time (b) Organisms must repair and maintain their structure (c) Movement of molecules does not take place among cells (d) Energy is essential for life process 38. What is common between the alveoli present in lungs and the villi present in the small intestine? (a) Both are involved in gaseous exchange (b) Both are involved in increasing the surface area of their respective organs (c) Both are involved in absorption of food (d) Both are involved in circulation of blood 39. The focal length of an optical device is 2 m. The power of lens is (a) 0.5 D (b) 2 D SAMPLE PAPER 9 (c) 1 D (d) 50 D 40. A ball is placed at 80 cm in front of a plane mirror. The distance between the ball and its image is (a) 80 cm (b) 40 cm (c) 100 cm (d) 160 cm 41. Choose the forms in which most plants absorb nitrogen. (a) Proteins, urea and nitrogen (b) Urea, atmospheric nitrogen and nitrates (c) Proteins, nitrates and nitrites (d) Urea, nitrates and nitrites

220 CBSE Sample Paper Science Class X (Term I) 42. If salivary amylase is lacking in the saliva, which of the following events in the mouth cavity will be affected? (a) Proteins breaking down into amino acids (b) Starchs breaking down into sugars (c) Fats breaking down into fatty acids and glycerol (d) Absorption of vitamins 43. A spherical converging mirror of radius 30 cm is placed in water. Its focal length in air and water differs by (a) 30 cm (b) 10 cm (c) zero (d) 15 cm 44. M P S In the given figure, S is the position of the screen on which a clear image of a distant object is formed by the mirror M. Some observations from this experiment are (i) the image formed will be virtual and small in size (ii) if the object moves closer towards the mirror, the image will also move towards the mirror. (iii) a virtual image cannot be obtained on screen (iv) No image is obtained on screen Which of the following statements is correct ? (a) (i) and (iv) (b) (iii) and (iv) (c) (i) and (ii) (d) (i), (ii), (iii) and (iv) 45. In the glass slab experiment four students A, B, C and D did the following A: kept the eyes far from the glass slab while placing both the pins P3 and P4 . B: kept the eyes close to glass slab while placing both the pins P3 and P4 . C: kept the eyes close to the glass slab while placing pin P3 and far from the slab, while placing pin P4 . D: kept the eyes far from the glass slab while placing pin P3 and close to the slab, while placing pin P4 . P1° P2° SAMPLE PAPER 9 P3° P4° The correct procedure is followed by which student? (a) A (b) B (c) C (d) D

CBSE Sample Paper Science Class X (Term I) 221 46. An object 2 cm in size is placed 30 cm in front of concave mirror as shown O P F 15 cm What will be the size of the image formed? (a) -1 cm (b) -2 cm (c) 2 cm (d) 1 cm 47. The speed of light in a transparent medium is 0.6 times that of its speed in vacuum. What is the refractive index of medium? (a) 0.6 (b) 1 (c) 1.67 (d) 16.7 48. A pencil manufacturing unit tested few elements on the basis of their physical properties. Properties WX Y Z Lustrous Yes No No Yes Brittle Yes No No Yes Electrical conductivity Yes No No 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 section. Attempt any 10 questions from this section. The first attempted 10 questions would be evaluated. Case I Rajat is a skilled painter. He mixed a white colured powder compound A with water. The compound A reacted vigorously with water to produce a compound B and large amount of heat. Then, Rajat used the compound B for white washing the walls. Customer was not satisfied with Rajat’s work as walls were not shining. But Rajat guaranteed him that the walls would shine after 2-3 days. And after 3 days of whitewash, the walls become shiny. Water SAMPLE PAPER 9 Compound A 49. Name the compound A that Rajat mixes with water. (a) Calcium (b) Calcium oxide (c) Calcium carbonate (d) Calcium hydroxide 50. Name the compound B that Rajat got after mixing A with water. (a) Calcium (b) Calcium oxide (c) Calcium carbonate (d) Calcium hydroxide

222 CBSE Sample Paper Science Class X (Term I) 51. What type of reaction has occurred here ? (a) Decomposition reaction (b) Displacement reaction (c) Double displacement reaction (d) Combination reaction 52. Which of the following reactions is responsible for shiny appearance of the walls ? (a) CaO + H 2 O ¾® Ca(OH) 2 (b) Ca + CO ¾® CaCO 3 (c) Ca(OH) 2 + CO 2 ¾® CaCO 3 + H 2 O (d) CaCO 3 + H 2 O ¾® Ca(OH) 2 + CO 2 Case II Respiration is a catabolic process which involves the breakdown of food or complex molecules into simpler products, with the release of energy. Four students experimented to show that CO2 is released during respiration. Given below are four different set-ups, marked as (a), (b), (c) and (d) used by each one of the student to show that carbon dioxide is released during respiration. Only one of them get the correct results. KOH KOH solution solution Water Water Dry gram seeds Boiled gram seeds (a) (b) KOH KOH solution solution Water Water Germinating gram seeds Wet and germinated gram seeds (c) (d) 53. Germinating seeds are used to demonstrate this experiment, because they carry out (a) active respiration (b) slow respiration (c) fast respiration (d) Either ‘a’ or ‘b’ 54. In which of the experimental setup, the water level will rise up in the bent tube ? (a) A (b) B (c) C (d) D SAMPLE PAPER 9 55. Which set up will give the correct result? (a) Set up with dry gram seeds (b) Set up with boiled gram seeds (c) Set up with germinating gram seeds (d) Set up with wet and germinated gram seeds 56. What will happen if KOH solution is not used in the small test tube in the experimental set up to show CO 2 is released during respiration? (I) CO 2 will not be produced by seeds. (II) Water level will not rise up in tube. (III) CO 2 will produced in large volume by germinating seeds. (IV) CO 2 produced by the germinating seeds will not be absorbed. (a) (II) and (IV) (b) (I) and (II) (c) (III) and (IV) (d) (I) and (IV)

CBSE Sample Paper Science Class X (Term I) 223 Case III Rahul wanted to study the properties of a convex lens. He demonstrated an experiment in which his set-up is shown as below. He placed the object between F1 and 2F1 on the left side of lens and draw the image formation on the sheet. A F2 B¢ 2F1 B F1 O 2F2 A¢ When he showed this to his teacher, teacher told him that he committed mistake while tracing the ray diagram. 57. Which mistake was done by him in this experiment? (a) Ray is not correctly traced (b) Position of image is wrong (c) Lens is tilted (d) Direction of travelling of ray is incorrect 58. If the ray passing from point O is inclined at 30° with principal axis, then what will inclined of this ray after passing through lens with principal axis? (a) 30° (b) 60° (c) 0° (d) 90° 59. What will be the height of image when object is of 9 cm in height and magnification is -3? (a) 27 cm (b) 3 cm (c) - 3 cm (d) - 27 cm 60. His friend suggested him same precautions while doing this experiment as follows (i) The convex lens should be thin and of small aperture for obtaining the distinct image (ii) Use a very sharp tipped pencil to draw thin lines to represent incident and refracted rays. (iii) The principal axis of the convex lens should be horizontal i.e., the lens should be placed vertically. (iv) To determine the focal length, the distance between the convex lens and the object should be measured horizontally. Which one of the above combination is correct? (a) (i) and (iv) (b) (ii), (iii) and (iv) (c) (iii) and (iv) (d) (i), (ii) and (iii) SAMPLE PAPER 9

OMR SHEET SP 9 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) 225 Answers 1. (b) 2. (c) 3. (d) 4. (b) 5. (d) 6. (a) 7. (c) 8. (b) 9. (a) 10. (c) 11. (b) 12. (a) 13. (c) 14. (c) 15. (b) 16. (a) 17. (a) 18. (c) 19. (b) 20. (b) 21. (d) 22. (a) 23. (c) 24. (c) 25. (c) 26. (c) 27. (a) 28. (b) 29. (b) 30. (b) 31. (d) 32. (c) 33. (a) 34. (b) 35. (b) 36. (c) 37. (c) 38. (b) 39. (a) 40. (d) 41. (d) 42. (b) 43. (c) 44. (d) 45. (a) 46. (b) 47. (c) 48. (b) 49. (b) 50. (d) 51. (d) 52. (c) 53. (a) 54. (c) 55. (c) 56. (a) 57. (b) 58. (a) 59. (d) 60. (d) EXPLANATIONS 1. When potassium iodide is reacted with lead 7. The chemical reaction between aluminium nitrate solution, yellow precipitate of lead and oxygen is can be written as : iodide is formed. The reaction take place as 4Al(s) + 3O2(g) ¾® 2Al2O3 2KI(aq)+ Pb(NO3)2(aq) ¾® 2KNO3(aq) + PbI2(s) In this reaction, two reactants, Al and O 2 (Yellow reacts with each other and form single ppt.) product, i.e. aluminium oxide Al2O3. Hence, 2. (c) When red lead oxide is heated strongly, it this reaction is categorised as combination forms lead monoxide and oxygen gas 2 Pb3O4 ¾D®6PbO + O2 ­ reaction. 3. Zinc, iron, magnesium and aluminium are more 8. The term ‘parent acid’ and ‘parent base’ are reactive than hydrogen. Therefore, undergoes displacement reaction with dil. H2SO4. used to describe the original compounds that Hydrogen is displaced by these metals from its solution (i.e. H2SO4). combined to make the salt. So, potassium During this reaction, hydrogen gas is evolved. carbonate salt can be formed from H2CO3 Zn + H2SO4 ¾® ZnSO4 + H2 ­ (parent acid) and KOH (parent base). 2 Fe + 3H2SO4 ¾® Fe2(SO4 )3 + 3H2 ­ Mg + H2SO4 ¾® MgSO4 + H2 ­ H2CO3 + 2KOH ¾® K2CO3 2 Al + 3H2SO4 ¾® Al2(SO4 )3 + 3H2 ­ Carbonic acid Potassium hydroxide Hence, option (d) is correct. (Parent acid) (Parent base) Potassium carbonate 4. In equation (b), (Salt) 2KI(aq)+ Pb(NO3)2(aq) ¾®2KNO3(aq) + PbI2(s) + 2H2O Total no. of atoms of all the elements are equal on both sides of equation. Hence, it is a 9. Chloroform gets slowly oxidised by air in Water balanced equation. presence of light to an extremely poisonous 5. As the pH of acid is below 7, so the letter which denotes the area of the graph where both gas, i.e. carbonyl chloride wihich is also sulphuric acid and salt are present after addition of excess sulphuric acid to sodium known as phosgene. bicarbonate is D. CHCl3 + O2 ¾S¾un¾lig¾ht® COCl2 6. The reaction of aluminium with copper sulphate solution is (Phosgene) 3CuSO4 + 2Al ¾® 3Cu + Al2(SO4)3 The substance which gets oxidised is called Hence, to avoid the oxidation of chloroform to reducing agent. Hence, in the given reaction, Al phosgene, it is stored in dark coloured bottles. is oxidised and acts as reducing agent by gaining oxygen atoms and forms Al 2(SO4)3. 10. The reaction (c) is balanced and have correct SAMPLE PAPER 9 states of reactant and products. 2KClO3(s) ¾® 2KCl(s) + 3O2(g) 11. (ii) Stomach is a J-shaped part of the alimentary canal. This serves as storehouse of food where partial digestion takes place through the secretion of gastric glands. Gastric glands secrete HCl, pepsin and mucus. Incorrect options can be corrected as : (i) Buccal cavity : It consists of two major parts, i.e. tongue and teeth. (iii) Pancreas : It is connected to the small intestine and secretes pancreatic juice.

226 CBSE Sample Paper Science Class X (Term I) (iv) Small intestine : It is longest part of 18. Here, the emergent rays are parallel to the alimentary canal and it is the site of direction of the incident rays. Therefore, a complete digestion of food into different rectangular glass slab could be inside the box. components. 19. A 12. The correct labelling is (i)-Right auricle, 55º (iii) pulmonary artery, (ii) aorta. B Q Right auricle receives deoxygenated blood P from the body. Pulmonary artery carries deoxygenated blood from the heart to the r1 lungs. Aorta carries oxygenated blood from the r2 heart to the body. SC R 13. The blood leaving the tissues becomes richer in carbon dioxide (CO2). When the oxygenated D blood passed through the capillaries, it gives oxygen to the cells and at the same time, Here, Ði = 55° carbon dioxide produced during respiration Ðr1 = Ðr2 = 40° [alternate angles] enters into blood. As, emergent ray is parallel to incident ray, 14. (iii) Lungs are the primary organ of respiration \\ Ði = Ðe = 55° in humans and other vertebrates. The primary function of the lungs is to facilitate the exchange Incident ray goes from rarer to denser that’s of gases between the blood and the air. why Ði > Ðr. Incorrect options can be corrected as : 20. Plane mirror produces a magnification of +1, convex mirror always forms a virtual and erect (i) Nasal passage : It serves as the zone of image, power of concave lens is always conduction of air. negative and bottom of tank appears to be raised due to refraction of light. (ii) Cartilagenous rings : They are present in windpipe (trachea) and ensure it does not 21. S collapse. i2 B (iv) Alveoli : Balloon-like structures located R inside lungs and these structures increase the surface area for the exchange A of gases. r2 r1 15. The opening and closing of the pore is a function of the guard cells. The guard cells D swell when water flows into them, causing the stomatal pore to open. Similarly, the pore DQ C closes if the guard cells shrink. i1 16. The correct matches are as follows. P Kidneys (A) has large number of filtration The net deviation suffered by incident ray is D. units called nephrons packed closely together. Ureter (B) connects the kidneys with the \\ i1 = D + r1 [opposite angles] urinary bladder (C) which is the temporary Þ D = i1 - r1 reservoir for the urine. 22. The correct path of ray among the given lens The waste material is brought to the kidneys by convex lens is given as by the renal arteries ( D). SAMPLE PAPER 9 F1 F2 17. Kerosene is the liquid whose mass density is less than that of water but it is optically denser 23. Due to atmospheric refraction, the day is than water. lengthened about 4 minutes. Because sunrise occurs two minutes before the actual sunrise and sun sets 2 minutes after the actual sunset.

CBSE Sample Paper Science Class X (Term I) 227 24. Only angles i and e are correctly marked. The does not dissociate completely into free ions. rest are corrected as shown. Hence, the bulb will not glow. d e In (IV) setup, the electrolyte is lemon juice which contains citric acid (strong acid). So, it i rr will dissociates into free ions to conduct electricity. Hence, the bulb will glow. 25. CaCO3 ¾D® CaO + CO2 ­ Calcium Carbon 31. A is false and R is true. The elements which Limestone oxide form acidic oxides are non-metals. Metal oxides are basic in nature, therefore gives dioxide hydroxide ions in water. This reaction is endothermic in nature as it 32. A is true and R is false. Non-metals accept electrons while metal donate electrons to requires heat energy to proceed and CO 2 gas is hydrogen ion of acid. evolved in this reaction. 33. Both A and R are correct and R is the correct 26. The concentration of hydrogen ions is explanation of A. inversely related to its pH according to the following expression : On putting few drops of iodine in starch pH = - log[H+] solution containing saliva, no blue/black colour is observed because of the enzyme, i.e. salivary So, according to graph, the pH value touched amylase which is present in saliva and breaks the highest in 2008. Hence, the concentration of down the starch molecule into sugar. H+ is lowest in 2008. 34. Both A and R are true but R is not correct 27. Zinc, magnesium, iron and calcium are more explanation of A. reactive than hydrogen. Therefore, they displace hydrogen from HCl and undergo As the temperature of medium increases its displacement reation. density decreases due to separation of molecules and hence the refractive index 28. The ionic compounds are crystalline solids and decreases. When a ray travels from vacuum to hard in nature. Hence, they have high melting a medium, then the refractive index of that point and conduct electricity in aqueous medium (m ) is the absolute refractive index of solution. that medium. So, according to the information given in table, 35. Amphoteric oxides are those oxides which Q and R substances have high melting points shows the properties of both acid and bases. and good conductor of electricity in aqueous So, the elements B and D form amphoteric solution. So, Q and R are ionic compounds. oxides as they react with both HCl and NaOH to evolve H2 gas. 29. Both (II) and (III) reasons are correct. Baking soda is basic in nature because when it mixes 36. Plants give off gaseous wastes like CO 2 and O2 with an acid, it changes pH level. Therefore, it through stomata and lenticels during is basic in nature. In basic medium, turmeric respiration and photosynthesis. Other waste gives reddish tinge. Hence, the stain of products include gums, resins, tannins, turmeric turns red on scrubbing with baking essential oil, etc. soda. 37. In multicellular organisms, movement of the 30. In (I) setup, the electrolyte is dil. HCl solution molecules occurs between the cells also. The SAMPLE PAPER 9 which can produce free ions on dissociation in movement of materials (molecules) in and out water to conduct electricity. of the cells is carried out by a number of methods like diffusion and osmosis. In (II) setup, the electrolyte is glucose solution Depending upon the energy requirements, which does not conduct electricity as it does these can be active or passive. not dissociate into free ions in water. Hence, the bulb will not glow. The growth of a living organism starts with the division of its cells. All living things have an In (III) setup, the electrolyte is alcohol organised structure, which if breaks down dissolved in water which does not conduct leads to various diseases, disorders and even electricity because it is very weak acid and death. Therefore, the living things have to repair and maintain their structures through various

228 CBSE Sample Paper Science Class X (Term I) processes. These life processes require energy Þ v = -30 cm which is obtained from food. Image will be formed at centre of curvature, real 38. The villi are present in the inner lining of the and inverted and of the same size as the object. small intestine, while alveoli are present in Hence, the size of image formed is –2 cm. the lungs. Both are involved in increasing the surface area of their respective organs. Villi 47. As we know that, facilitates nutrient absorption, while alveoli m=c facilitates rapid exchange of oxygen and v carbon dioxide. Given, v = 0.6 c 39. Here, f = 2 m Þ P = 1 \\ m = c = 1 » 1.67 f 0.6 c 0.6 Þ P = 1 = 0.5 D 2 48. The elements X, Y and Z were dicarded for usage by the pencil company because for pencil 40. The distance between object and image in manufacturing graphite is used which is brittle, case of plane mirror is, lustrous, good conductor of electricity and have D = 2 ´ distance of object from mirror high melting point and W has all these = 2 ´ 80 = 160 cm properties. Hence, W is not discarded among the others. 41. Plants need nitrogen for the process of protein synthesis. However, they cannot 49. Rajat mixed calcium oxide with water which utilise nitrogen as it is. It is converted into inorganic form as nitrate and nitrite and in produces calcium hydroxide and heat. organic form as urea by the action of various microorganisms. It is then taken up by the CaO+ H2O ¾® CO(OH)2 + Heat plants for various processes. (A) Calcium hydroxide 42. The enzyme salivary amylase is present in the mouth . This enzyme breaks the starch (B) molecules in the food into maltose. The absence of this enzyme, thus affects the 50. Calcium hydroxide breakdown of starch into simpler sugar molecules. CaO + H2O ¾® Ca(OH)2 + Heat 43. The focal length of spherical mirror doesn’t (A) (B) depend on the surrounding medium. 51. When calcium oxide mixed with water, 44. The mirror is convex, so the image formed will be virtual, erect and small in size. If the they combines and form calcium hydroxide. object moves closer to mirror, then the image will also move closer to the mirror. As the CaO + H2O ¾® Ca(OH)2 + Heat image formed by this is virtual so it cannot be obtained on screen. 52. Ca(OH)2 + CO2 ¾® CaCO3 + H2O 45. The eyes must be kept far from the glass slab CaCO3 is responsible for shiny appearance of while placing both the pins P3 and P4. walls. 46. Here, u = -30 cm 53. Germinating seeds are used to demonstrate f = -15 cm ho = 2 cm respiration experimentally because they carry Using mirror formula, out active respiration and release CO 2 in the 1+1=1 process. vu f 54. The experimental setup ‘C’ will show the rise in Þ 1=1 -1 water level in the bent tube because KOH v fu absorbs carbon dioxide and creates vaccum in the flask. The air present in the bent tube moves = 1 + 1 = 2 -1 = -1 into the flask. This pulls the water in the bent -15 30 -30 30 tube further up. SAMPLE PAPER 9 55. The setup (C) is the correct set up for the experiment. In the experiment, moist gram seeds are taken as they are actively respiring and releasing CO2. 56. If KOH is not used in the given experiment, then there will be no absorption of carbon dioxide relased by germinating seed. Also, there will be no rise up in the level of water in the bent tube.

CBSE Sample Paper Science Class X (Term I) 229 57. The position of image was wrongly traced by 59. Given, ho = 9 cm Rahul. So, the correct ray diagram that shows m= -3 the real position and size of image corresponding to the position of the object AB Magnification, m = hi is shown below. ho A Þ -3 = hi 9 2F1 B F1 O F2 B' 2F2 hi = -27 cm A' 60. Some precautions are required while performing this experiment as convex lens is 58. When the ray passing from optical centre of thin and of small aperture, pencil should be the lens, it passes undeviated as a straight line. sharp tipped, lens should be vertical with So, if the ray initially makes an angle of 30° principal axis and to determine the focal with principal axis, hence after refraction, it length, the distance between the convex lens makes same angle of 30° with principal axis. and the screen should be measured horizontally. SAMPLE PAPER 9

SAMPLE PAPER 10 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. Anam took calcium oxide in an iron container and slowly added water to it. What would she observe? (a) The pop sound was observed (b) The white fumes were observed and solution become hot (c) The hissing sound was produced and solution become hot (d) The solution become cold 2. Identify the gas A is the following experiment. Gas A Lime water Dil. HCl (a) H2 Na2CO3 (c) O2 (b) CO2 (d) Cl2

CBSE Sample Paper Science Class X (Term I) 231 3. Metal Water Metal hydroxide Gas Which of the following two combinations are correct? Metal Gas evolved 1. Zinc P 2. Iron O 3. Potassium O 4. Sodium P (a) 1 and 2 (b) 1 and 4 (c) 2 and 4 (d) 3 and 2 4. Which of the following correctly represents a balanced chemical equation? (a) Al2O3 + 3HCl ¾® AlCl3 + 3H2O (b) 2Al2O3 + 6HCl ¾® 2AlCl3 + 3H2O (c) Al2O3 + 3HCl ¾® 2AlCl3 + 3H2O (d) Al2O3 + 6HCl ¾® 2AlCl3 + 3H2O 5. The graph given below depicts a neutralisation reaction, HNO3 + NaOH ¾® NaNO3 + H 2O. The pH of a solution changes as we add excess of NaOH to nitric acid. 14 D pH 7 C value B A O Volume of NaOH 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 calcium oxide with hydrochloric acid solution, SAMPLE PAPER 10 CaO + 2HCl ¾® CaCl2 + H2O Which option in the given table correctly represents the substance reduced and the oxidising agent? Substance reduced Oxidising agent (a) CaO CaO (b) HCl H2O (c) H2O CaCl 2 (d) CaCl2 HCl

232 CBSE Sample Paper Science Class X (Term I) 7. The chemical reaction between sodium and oxygen can be categorised as, (a) displacement reaction (b) decomposition reaction (c) combination reaction (d) double displacement reaction 8. Which of the given option correctly represents the parent acid and base of sodium sulphate ? Parent acid Parent base (a) HCl NaOH (b) H2CO3 K(OH) 2 NaSO4 (c) H3PO3 NaOH (d) H 2 SO 4 9. What happens, when zinc reacts with dilute sulphuric acid? (a) Red coloured gas is evolved with sweet smell (b) Green coloured gas is evolved with foul smell (c) Colourless and odourless gas is evolved which burns with a pop sound (d) Colourless, pungent smell is evolved which burns with a pop sound 10. The ant sting can be cured by rubbing soap on the affected area because (a) it contains citric acid which neutralises the effect of formic acid (b) it contains sodium hydroxide which neutralises the effect of formic acid (c) it contains magnesium hydroxide which neutralises the effect of formic acid. (d) None of the above. 11. Carefully study the diagram of the human circulatory system with labels (i) to (iv). Select the option which gives correct identification and main function and/or characteristics. (i) (ii) (iii) (iv) SAMPLE PAPER 10 (a) (i)-Right auricle ® It contracts and the blood moves to the vena cava. (b) (ii)-Left auricle ® It contracts and the blood moves to the pulmonary artery. (c) (iii)-Right ventricle ® It contracts and the blood moves to the left ventricle. (d) (iv)-Left ventricle ® It contracts and the blood moves to the aorta. 12. Which structures contains muscles that contracts when breathing in? Bronchus Xheart Cut end of rib Z (a) Only X Y (d) X, Y and Z Lung (c) Y and Z (b) X and Y

CBSE Sample Paper Science Class X (Term I) 233 13. Gastric digestion takes place efficiently in (a) acidic medium (b) alkaline medium (c) neutral medium (d) highly alkaline medium 14. The figure given below shows diagram of human excretory system with labels (i) to (iv). Identify the correct label with its function. (i) (ii) (iii) (iv) (a) (i) Renal artery - Carries purified blood away from the kidney. (b) (ii) Renal vein - Carries blood to the kidneys along with nitrogenous waste materials. (c) (iii) Ureter - Carries urine to the urinary bladder. (d) (iv) Aorta - Carries deoxygenated blood to the kidneys 15. Identify the correct statement regarding the human digestive system. Mouth/Buccal cavity Oesophagus (food pipe) Salivary glands Tongue Liver Stomach Diaphragm Pancreas Gall bladder Large intestine (stores bile) (colon) Bile duct Rectum Appendix SAMPLE PAPER 10 Small intestine (a) The HCl creates an acidic medium that facilitates the action of enzyme pepsin (b) The length of small intestine differ in various animals depending upon their habitat (c) The finger-like projections present in stomach increases the surface area for absorption (d) The end products of digestion of food are glycerol, starch, amino acids and fatty acids

234 CBSE Sample Paper Science Class X (Term I) 16. Observe the diagram of human circulatory system. C A RA LA RV LV B D Match the labelling referred in Column I and correlate with Column II. Column I Column II A 1. It carries oxygenated blood to the body B 2. It carries oxygenated blood from the lungs C 3. It carries deoxygenated blood to the heart D 4. It carries deoxygenated blood to the lungs Codes A B CD (a) 3 2 1 4 (b) 1 4 3 2 (c) 2 3 4 1 (d) 2 3 1 4 17. In torches, search lights and head lights of vehicles, the bulb is placed (a) between the pole and the focus of the reflector (b) very near to the focus of the reflector (c) between the focus and centre of curvature of the reflector (d) at the centre of curvature of the reflector 18. Light source placed at a distance shoots a beam of light parallel to principal axis of a concave mirror and plane mirror as shown. SAMPLE PAPER 10 After the reflection, beam of light will converge at (a) focus and infinity respectively (b) infinity and focus respectively (c) at radius of curvature and pole respectively (d) at pole and focus respectively

CBSE Sample Paper Science Class X (Term I) 235 19. Which of the following is the correct measured of the angles of incidence and emergence by a student? i i i i (a) (b) (c) (d) ee e e 20. If a beam of yellow and a beam of green colour are incident at the same angle on the inclined surface of a prism from air medium and produce angles of refraction y and g respectively, which of the following is correct? (a) y = g (b) y > g (c) y = 1 (d) y < g g 21. Consider the refractive indices of; Kerosene 1.63, crown glass 1.49, diamond 2.42. Based on this data, arrange the speed of light through them in increasing order. (a) Speed of light in diamond < speed of light in crown glass < speed of light in kerosene. (b) Speed of light in diamond < speed of light in kerosene < speed of light in crown glass. (c) Speed of light in crown glass < speed of light in Kerosene < speed of light in diamond. (d) Speed of light in kerosene < speed of light in diamond < speed of light in crown glass. 22. X White light Y Prism SAMPLE PAPER 10 Examine the above figure and state which of the following option is correct? (a) Colour X is red and colour Y is violet (b) Colour Y is yellow and colour X is blue (c) Colour Y is red and colour X is violet (d) Colour X is blue and colour Y is red 23. Which of the following statement is correct regarding the propagation of light of different colours of white light in air? (a) Red light moves with fastest speed (b) Blue light moves faster than green light (c) All colours of light move with same speed (d) Yellow moves with fastest speed 24. A student obtains a sharp image of the distant window (W) of the school laboratory on the screen (S) using the given concave mirror (M). To determine its focal length, what distance should he measure to get the focal length of the mirror? W SM (a) MS W SM (d) MW-SM (b) SW (c) WM

236 CBSE Sample Paper Science Class X (Term I) 25. Magnesium + O2 ¾H¾ea¾t¾ed® X ¾+¾H¾2O® Magnesium hydroxide Identify the correct option from the given table which represents the type of reaction. Endothermic Gas evolve (a) No Yes (b) Yes No (c) Yes Yes (d) No No 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. 26. In which sample the concentration of H + ion is the highest? pH Value (a) A (b) B ABCD E (d) E Samples (c) C 27. Which of the following statement is correct about reactivity series? (a) The arrangement of elements in increasing order of reactivity (b) The arrangement of elements in decreasing order of reactivity (c) The arrangement of oxides of elements in increasing order of reactivity (d) The arrangement of elements with water in increasing order of reactivity 28. The table shown below gives the information about four elements, A, B, C and D. Substance Soluble in water Electrical conductivity A P Good B O Bad C P Good D O Good Identify the ionic compound from the given substance. SAMPLE PAPER 10 (a) A and B (b) B and C (c) C and D (d) A and C 29. A teacher gave two test tubes, one containing water (A) and the other containing sodium hydroxide solution (B) to the students and asked them to identify the test tube containing sodium hydroxide solution. The following observation are made by students. I. Litmus paper turns blue in test tube (B). II. No change on litmus paper in test tube (A). III. Phenolphthalein turns pink in test tube (B). IV. Slight change in colour in test tube (A) by adding phenolphthalein.

CBSE Sample Paper Science Class X (Term I) 237 Which of the following observations is/are correct ? (a) I and III (b) II and III (c) I, III and III (d) II, III and IV 30. Colour pH Red 2 Orange red 4 Orange yellow 6 Green 7 Greenish blue 8 Blue 9 Dark blue 10 Vioiet 10.5 Equal volume of HCl and NaOH solutions of same concentration are mixed. What will be the colour and pH of the resulting solution? (a) Blue, pH = 9 (b) Green, pH = 7 (c) Orange red, pH = 4 (d) Dark blue, pH = 10 Direction (Q. Nos. 31-34) For given questions two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as 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 Magnesium wire is burned in the presence of oxygen. Reason Magnesium acts as a reducing agent. 32. Assertion AlCl3 is known as basic salt. Reason AlCl3 is a salt of strong acid and weak base. 33. Assertion Respiration is an exothermic reaction. Reason During respiration, glucose combines with oxygen to give carbon dioxide and water. This reaction also release some energy. 34. Assertion Lateral displacement is the perpendicular distance between incident ray and the emergent ray. Reason If a wider glass slab is used, then the lateral displacement is also larger. 35. The table given below provides the information about some salts, regarding their SAMPLE PAPER 10 common name and water of crystallisation. Salt Common name Water of crystallisation (i) Sodium hydroxide Caustic soda 1 (ii) Calcium oxychloride Bleaching powder 0 (iii) Sodium hydrogen carbonate Washing soda 2 (iv) Sodium carbonate Soda ash 10

238 CBSE Sample Paper Science Class X (Term I) Which of the following are correct about information given in table ? (a) (i) and (iii) (b) (iii) and (iv) (c) (i) and (ii) (d) (ii) and (iv) 36. Which of the following processes will not occur if the stomata get blocked? (a) Transpiration and respiration. (b) Transpiration, photosynthesis and respiration. (c) Respiration, transpiration and transportation. (d) Respiration and photosynthesis. 37. Digestion begins in the mouth. Which of the following statement is incorrect? (a) The tongue aids in the digestion of the food (b) The saliva changes some of the starch present in the food to sugar. (c) The tongue keeps the food in place in the mouth, while the food in being chewed. (d) The digestive juices can react more easily with food when chewed 38. How does the kidney dialysis machine function like a healthy kidney? (a) It deaminate excess amino acids to form urea (b) It regulates blood concentration (c) It removes nitrogenous waste products from the blood (d) It regulates the production of RBCs 39. If m 21 and m 31 be the refractive indices of medium number 2 and 3, respectively with respect to medium 1, then the value of refractive index of medium 3 with respect to medium 2 is, (b) m 21 (c) m 31 (d) m 21 ´ m 31 (a) m 21 + m 31 m 31 m 21 40. SAMPLE PAPER 10 The above lenses have focal length - 50 cm and 10 cm. They are combined to form a combination. This combination becomes (a) diverging lens of power 60 D (b) converging lens of power -25 D (c) diverging lens of power - 40 D (d) converging lens of power 0.08 D 41. Plants get rid of solid and liquid waste by (a) shedding of leaves, peeling of bark and decoloration of leaves (b) peeling of bark, falling of fruits and transportation (c) falling of fruits, shedding of leaves, peeling of bark (d) falling of fruits, maturing of plant, transportation 42. The left ventricle of the heart is thicker wall than the right ventricle (a) because it contains more blood (b) so that more deoxygenated blood can reach every part (c) because when blood is pumped, a strong pressure acts on it (d) because it receives blood from the lungs

CBSE Sample Paper Science Class X (Term I) 239 43. A Ray 1 Ray 1 Ray 2 Ray 2 Ray 3 Ray 3 Prism A student observes the diagram of path of a ray of light passing through a glass prism. He finds that for all angles of incidence the ray of light bends. Which of the following is correct about it? I. The ray bends towards the normal while entering into the prism and away from the normal while emerging out of the prism. II. The ray bends away from the normal while entering into the prism and towards the normal while emerging out of the prism. (a) Only I (b) Only II (c) I and II (d) Neither I nor II 44. A 10 mm long pin is placed vertically in front of a concave mirror. A 5 mm long image is formed at 30 cm in front of the mirror. The focal length of this mirror is (a) - 30 cm (b) - 40 cm (c) -15 cm (d) - 20 cm 45. Candle 3m Wall The height of above candle is 3 cm and it is placed at a distance of 3 m from a wall. How far from the wall must a concave mirror be placed in order to get a 9 cm high image on the wall? (a) 450 cm (b) 350 cm (c) 275 cm (d) 200 cm 46. SAMPLE PAPER 10 A child is standing in front of a plane mirror of length 58 cm. He noticed that he sees his full image in mirror. What is the height of child? (a) 1.32 m (b) 1.16 m (c) 1 m (d) 0.58 m

240 CBSE Sample Paper Science Class X (Term I) 47. m1 q2 q3 m2 q1 While looking at the above ray diagrams, Uma concluded the following (I) Medium 2 is denser than medium 1. (II) Bending of light depends upon the refractive index of medium. (III) Angle q 3 is the critical angle for medium 1 (IV) This is the phenomenon of total internal reflection Which one of the above statements are incorrect? (a) (III) (b) (II) and (IV) (c) (III) and (IV) (d) (II), (III) and (IV) 48. Element Malleable Ductile Lustre A Yes Yes Yes B No No Yes C Yes No Yes D Yes No Yes Which of the above elements can be used for making jewellery ? (a) A and B (b) B and C (c) D Only (d) A Only Section C This section consists of 6 multiple choice questions with an overall choice to attempt any 5. In case more than desirable number of questions are attempted, ONLY first 5 will be considered for evaluation. Case I An indicator is used to confirm the presence of an acid, a base or a neutral solution. The pH scale measures how acidic or basic a substance by making use of hydrogen ion concentration in them. The table given below showes the pH value and colour change shown by substance P, Q, R, S and T by using universal indicator. SAMPLE PAPER 10 Substance pH Colour shown by universal indicator P 6 Greenish yellow Q 12 Navy blue R 0 Dark red S 8.5 Greenish blue T 3 Orange

CBSE Sample Paper Science Class X (Term I) 241 Read the above passage carefully and answer the following questions: 49. Which of the following is/are true about substance Q? I. It is the strongest base among the given substance. II. It is used in antacids. III. It turns blue litmus paper to red. IV. None of the above (a) I, II (b) II, III (c) I, II, III (d) Only IV 50. Which of the following statement is correct about substance S? (a) It can be used as baking soda (b) It is used in fire extinguisher (c) It turns red litmus paper to blue (d) All of the above 51. Arrange the substance P, Q and T in increasing order of their acidic strength. (a) T < P < Q (b) P < T < Q (c) Q < P < T (d) P < Q < T 52. Which of the following cannot act as an indicator? (a) Methyl orange (b) Methyl yellow (c) Turmeric (d) Red cabbage juice Case II The figure shown below represents an activity to prove that chlorophyll is necessary for photosynthesis. During this activity potted plant with variegated leaves is kept in dark room for 3 days. After this, keeps the plant in sunlight for 6 hours. Then, pluck a leaf and dip in boiling water for few minutes and after that in alcohol. Then, iodine test is performed on the leaf. (a) (b) 53. The part of the leaf which was originally green turns (a) pink (b) blue/black (c) green (d) brown SAMPLE PAPER 10 54. Why is the plant kept in dark for three days? (a) To destarch its leaves (b) To remove all the carbon dioxide (c) To remove all the oxygen (d) To remove all the water 55. The function of alcohol is to remove (b) starch (d) chlorophyll (a) cell wall (c) water

242 CBSE Sample Paper Science Class X (Term I) 56. Which of the following steps can be followed for better iodine test? (i) Boiling in water. (ii) Keeping the plant in dark for more days. (iii) Boiling in alcohol. (iv) Cutting of leaves. Choose the correct option. (a) (i) and (ii) (b) (ii) and (iv) (c) (i) and (iii) (d) (i) and (iv) Case III. Rohit performs an experiment on determining the focal length of a convex lens. He kept a lighted candle at one end of table, a screen on its other end and the lens between them as shown in figure below. The positions of the three are adjusted to get a sharp image of the flame of candle on the screen. For more information he replaced the flame of candle by a distant lamp on a far away electric pole. Screen Candle (Object) (Image) Lens 57. When the source is changed to distant lamp, then the image will be focussed (a) beyond 2 f (b) at f (c) between f and 2 f (d) at 2 f 58. He noted some observations from this demonstration and concluded the following (I) As he moves the screen, the image gets focussed beyond 2 f of the lens. (II) The parallel rays originating from a distant object and incident on a convex lens may not be parallel to its principal axis. (III) As, he changed the source, the size of the image will also get changed (IV) Size of image will be more after the candle flame was replaced. Which one of the following combination is incorrect from the above statements? (a) (II) and (III) (b) (I) and (II) (c) (I) and (IV) (d) (II) and (IV) 59. An object 50 cm tall is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the focal SAMPLE PAPER 10 length of the lens. (a) 7.14 cm (b) 5 cm (c) 20 cm (d) 6.5 cm 60. Which is not the property of convex lens? (a) It forms a real and inverted image (b) It gives magnified image (c) It gives small point sized image (d) It is used as rear view lens

OMR SHEET SP 10 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)