2014-G12-Physics-E

For Your Information and dental X -ray are made for no strong reason and m ay doSource*or normal radobon more harm than good. Every X-rays exposure should have a definite justification that outweighs the risk. T h e other sources include radioactive w aste from nuclear facilities. i -V\" hospitals, research and industrial establishments, colour television, luminous watches and tobacco leaves. A smoker not onty inhales toxic sm oke but also h aza rdo us radiation. L o w level background radiation from natural sources is normally considered to be harmless. Howovor. higher levels of exposure are certainly dam aging. W e cannot avord exposure to radiation. H ow ever, the best advice is to avoid unnecessary exposure to a n y kind of ionizing radiation. 21.12 B IO LO G IC A L E F F E C TS O F RADIATION Tibi* 212 To study the effects of radiation, w e need to define som e ofR iU tN* Bkfegkal Efl*C«K*n*M (RBE)eX. (4lMXMUi. H,Viorni mn W K U V the units of radiation. T h e strength of the radiation source isMtV indicated by its activity m easured in becquorel (B q ). O n eM m w NnM m M1'O0l!t•o»«*»»>) becqucrcl is o n e disintegration per second. A larger unit isN *M tool *X»» curie (C i) which equals 3.7 x 10’: disintegrations per second. T h e effect of radiation o n a body absorbing it relates to a quantity called absorbed dose D defined as the energy E D=„absorbed from ionizing radiation per unit m ass m of the absorbing bedy. £ (21.10) 250

Its SI unit is gray (G y ) defined as one joule per kilogram. Table 21.3 Average « M c n Ooaet h * a mwoer 1 G y = 1 Jkg ’ et a w m vxree* e» e n z n g redetonA n old unit is rad, an acronym for radiation absorbed dose. 1 rad = 0.01 G y Type* of Expo*ure mSviEqual doses of different radiations do not produce same W e v « « « lor •yew 10 Redefton fromnude* power 10biological effect Fo r the sam e absorbed dose. n-particJes lU U n W tiware 20 times m ore dam aging than X -rays. T h e effect also W M 'rvj « kfflKW I »depends on the part of the body absorbing the radiation. For ■atefi fc*•( t v (now not very 200example, neutrons are particularly more damaging to eyesthan other parts of the body. To allow this, the absorbed dose COrwrOlJis multiplied by a quality factor know n as relative biologicaleffectiveness o r R B E (Ta b le 2 1 .2 ). T h e equivalent dose D , of MevegatfeatXve*a n y absorbed radiation is defined as the product of absorbed Redadon lw > a try* route per 7J0dose and R B E of the kind of radiation being absorbed. leer M t u n s r dote alceed to 1000 genertt putte Iron rtf o a l WOO vorce* ter year 0. = O x RBE ....... (21.11) .Vcrxrv; to a men*! « i a oariM Ti mrm Type* dote lecerved bye 2M0 - e r * t r d In* g m l fuMc nT h e SI unit of equivalent dose is sieved (S v ). a yM rfro m a liM cm 1 Sv = 1 Gy x RBE U iu n n M ta U M ie 5CO» • y t r . ngoiedtoredetoncerA n old unit, the rem is equal to 0.01 Sv. .1*** 1 rem = 0.01 S v dosage >nT h e background radiation to w hich w o are exposed, on the rrnc/o » eveitaverage, is 2 m S v per year. D oses of 3 S v will cause radiationb um s to the skin. F o r w orkers in the n u d e a r facilities or 4 000 000 _ deatr> oT 60 percentm ines, a w eekly dose of 1 m S v is norm ally considered safe <* peopw ex(>2ted(Table 21.3).T h e dam age from a-particles is sm all unless the source 3000000enters the body, a and p-partidcs can cause redness and - ateoity lo r about twosores on the skin. S o m e other low level radiation cffed s are yeanloss of hair, ulceration, stiffening of the lungs, and a drop in 2000000the white blood cells which is followed by a sickness pattern - temporary tow letbMyof diarrhea, vomiting and fever known as radiation sickness(F ig 21.16), High levels of radiation m ay disrupt the blood 1000 000 — radueen sicknesscells seriously leading to diseases such a s anaem ia andleukaemia. Chrom osom e abnormalities or mutation m aycause delayed genotic effects such as cancer, eye cataractsand abnormalities in the future generations Th e se m aydevelop m any years after exposure to harmful radiationE x a m p l e 2 1 .3 : H o w m uch e n e rg y is absorbed by a m a n of 0 1-m ass 80 kg w ho receives a lethal w hole body equivalent ^.dose of 400 rem in the form of low energy neutrons for whichR B E factor is 10? 251

S olu tion:For Your Information R B E factor = 10 D . = 400 rem = 400 x 0.01 S v = 4 S v . D = ? Using Eq. 21.4 D °* — 0.4 G y R B E 10 y S in ce 1 G y is 1 J kg ’. hence total e n e rg y absorbed by the whole body = m 0 = 8 0 x 0 .4 G y = 32 JF*m t o » j e doum otor art, u v M to It is a very small am ount of therm al energy. O bviously, themonitor rsdobonroceivod by workers da m age done by ionizing radiation has nothing to do with«i nodonr tnoloos thermal energy. T h e harmful effects arise due to disruption of the normal functions of the tissues in w hich it is absorbed. 21.13 B IO L O G IC A L A N D M ED IC A L U S E S OF RADIATION Do You Know? Radioisotopes of m any elements can be m ade easily byRadtoocbvo wastes are ot throe t»p** bom bardm ent with neutrons and other particles. A s suchi.« .h g h to v d .n e d u m ardtcwl«v*t isotopes have be com e available and are inexpensive, theirA l th o i« wastes aro darvgarout lor use in m edicine, agriculture, scientific research andground water and land anvtronmam industries has expanded tremendously. Fo r Y o u r Inform ation Radioisotopes are used to find out what happens in m anyIt it vory d ffla rt to d t»p o «« off com plex chemical reactions and how they proceed. Similarlyradioactvo w a tte aatoly due to the* m biology, they have helped m investigating into chemicallong half tKae e g . P u 'ha ff M s a reactions that take place in plants and animals. B y mixing a24.000 years. therefore. it rom ans small am ount of radioactivo isotope with fertilizer, w e candangerous tor about 1.92.000 year*. easrty m easure how m u ch fertilizer is taken u p by a plant using radiation detector. From such m easurem ents, farmers know the proper am ount of fertilizer to use. Th ro u g h the use of radiation-induced mutations, improved varieties of certain crops such as rice, chickpea, wheat and cotton have been developed. Th e y have improved plant structure. Th e plants have show n m ore resistance to diseases and pest, and give better yield and gram quality. Radiation is also used to treat cancers Radioactivo tracers and imaging devices havo helped in the understanding and diagnosis of m a n y diseases. Tra ce rTe ch n iq u e s A radioactive isotope behaves in just the sam e w ay as the normal isotope inside a living organism. But the location and concentration of a radioactive isotope can be determined easily by measuring the radiation it emits. Th u s , a radioactive 252

isotope acts as an indicator o r tracer that m akes it possible to TaMa 21.4follow the course of a chemical or biological process. Th etechnique is to substitute radioactive atom s for stable atom s i»otoo» \"H IV , Eiampk*of the sa m e kind in a substance and then to follow the Sodom u*v 0»Tagg e d- atom s with the help of radiation detector in the u*.process. Tra ce rs are w idely used in medicine to detect -N Jm alignant tum ors and in agriculture to study the uptake of a iS h o m 137.275 II mfertilizer b y a plant. F o r exam ple, if a plant is given radioactivec arbon -14, it will use it in exactly the sa m e w ay as it always Iron 45 day* 129.110 Rnnuses stable carbo n -12. But the carbo n -14 releases \"ft 019 ftM TOp-radiations and thus by m easuring radioactivity in differentparts of the plant, the path taken by the carbon atoms can be n. Thyrodknown. Th is technique has helped to understand more lodno 6 l m n 014 K W -elaborately the complex process of photosynthesis. Th etracer technique w a s also used to identify faults in the ”1 Kamunderground pipes of the fountain system of the historicalShalim ar gardens of Lahore b y the scientists of Pakistan 072.064Atom ic Energy Commission. titty * 036.026 KiJTayM edical D ia g n o stics a n d Th o ra p y 006Tracers are widely used in medicine to study the process of -1 eoatyt 0035digestion and the w ay chemical substances m ove about mthe body.S o m e chem icals such as h ydrogen and sodium present inwater and food are distributed uniformly throughout the body.Certain other chemicals are selectively absorbed by certainorgans. R adio-iodine, for exam ple, is absorbed mostly by thethyroid gland, phosphorus b y bo nes and cobalt by liver. T h e ycan serve a s tracers. Sm all quantity of low activityradioisotope mixed with stable isotope is adm inistered byin je c tio n o r otherw ise to a patient and its location in diseasedtissue can be ascertained by m oans of radiation detectors.F o r exam ple, radioactive iodino c a n be used to check that aperson's thyroid gland is w orking property. A diseased orhyperactive gland absorbs m ore than twice the am ount ofnormal thyroid gland. A similar method can bo used to studythe circulation of blood using radioactive isotope sodium -24.Experim ents on cancerous cells have show n that those cellsthat multiply rapidly absorb m ore radiation and are moroeasily destroyed than normal cells by ionizing radiation.Radiotherapy with y-rays from cobalt-60 is often used in thetreatment of cancer. T h e y-rays are carefully focussed on tothe malignant tissue. Strict safety precautions are necessary253

for both patient and attendant medical staff. Radioactive iodme-131 is usod to combat cancer of the thyroid gland. Since iodine tends to collect in the thyroid gland, radioactive isotopos lodge whero they can destroy tho malignant colls. In some cases encapsulated 'seeds’ are implanted in the malignant tissue for local and short ranged treatment. For skin cancers, phosphorus-32 or strontium-90 m ay be used instead. Those produce p-radiation. Th e dose of radiation has to be carefully controlled otherwise the radiation could do more dam age than help. Patients undergoing radiation treatment often feel M. because the radiation also damages tho healthy cells. R adiography Th e y-rays radiographs are used in medical diagnosis such as internal imaging of the brain to determine precisely the size and location of a tumor or other parts of the body. Cracks or cavities in castings or pipes can also be detected by scanning. Any sudden increase in couni rate indicates a cavity within the object.Fig. 21.I T Th e gam m a camera is designed to detect y-radiations from sites in the body where a y-emitting isotope is located. An image as shown in Fig. 21.17. consisting of many dots of the y-emitting sources in the patient body is formed. Th e camera can also be used to obtain a sequence of images to observe an organ such as a kidney in action. 21.14 BASIC FO R CES O F NATURE Th e man has always desired to comprehend the complexity of nature in terms of as few elementary concepts as possible. Among his quest, in Feynman's words, has been the one for \"wheels within wheels', the task of Natural Philosophy being to discover the nn cr most wheels ifany such exist. A second quest has concentrated itselfwith the fundamental forces, which make the wheels go round and enmesh with one another. Although w e have been familiar with the basic forces and about some of the basic building blocks of the matter, but here w e are going to study the modern concepts about both of these. W e know that the basic forces are: 1 . Gravitational force 2 Magnetic force 3. Electric force 4 W eak nuclear force 5 Strong nuclear force 254

T h e electric and magnetic forces were unified to get an For Your Informationelectromagnetic force by Faraday and Maxwell, who were Com position of Matterable to prove that a current is induced in a coil whenever the UMOMmagnetic flux passing through the coil is changed; leaving ftbehind four fundamental forces, the strong nud ear force, the 10‘ melectromagnetic force, the weak nudear force and thegravitational force. These four fundamental forces of nature 10” mhave seemed for some time quite different from one another.Despite its different effective strength, the strong nudear Nucteusforce is effective only within sub-nudear distances and ‘ 10“ mtherefore, confines tho neutrons and protons within the NauQron or Protonnudeus. Th e electromagnetic force is long-range and causesall chemical reactions. It binds together atoms, molecules, lO^mcrystals, troes, buildings and you. This force acting on amicroscopic level is responsible for a variety of apparentlydifferent macroscopic forces such as fridion. cohesion andadhesion. T h e weak nuclear force is short range, liko thestrong nudear force, and is responsible for spontaneousbreaking up of the radioactive elements. It is a sort ofrepulsivo force of very short range (1 0 \" m ). It is usuallymasked by the effed of the strong and eledromagneticforces inside the nuclei. Th e gravitational force, like theelectromagnetic force, is again long range, extending uptoand beyond the remotest stars and galaxies. It keeps you. theatmosphere and the seas fixed to the surface of tho planet. Itgives rise to the ocean tides and keeps the planets moving intheir orbits around the Sun.Th e se widely disparate properties of the four basic forceshave not stopped the sdentists from finding a comm on causefor them all.O r e hundred years after the unification of electric andmagnetic forces into electromagnetic force, in 1979. thephysics nobel prize was conferred on Glashow. Weinbergand Abdus Slam for the unification of eledrom agnetic andweak forces.It is further expeded that a strong nudear force will Quarteventually unite with eledroweak force to make up a singleentity resulting in the grand unified olectro-nudear force.21.15 BUILDING B LO C K S O F M A TTERSubatomic partides aro divided into three groups.1 Photons 2. Leptons 3. Hadrons L ett man 10 \"m 255

Table 21.5 Ele m e nta ry particles are the b asic building blocks of matter.Quark* and Antiquark* All photons a nd leptons a re elem entary particles. H adrons are not elem entary particles but are com po sed of elem entaryName Charge particles c a lle d q u a rk s . S cie n tists n o w b e lio ve that all m atter belongs to either the quark group or the lepton group.Oo-n V -4 *Sear.* d ♦4e HadronsCham s *4®Tog c -4 ® 1 Antique rk* H ad ron s a re particles that experience the strong nuclear force. . In addition to protons, neutrons a n d m e so n s are hadrons. T h e 3 -4® particles e qu al in m a s s o r g rea te r than protons a re called I •to baryons and those lighter than protons a re c a le d m esons. e *4® T *4®-- 6 ♦4® Proton Leptons are particles that do not experience strong nuclear force. E lectron, m u o ns and neutrinos a re leptons. NMron Q u a rks Charge A cco rding to quark theory initiated b y M . G e ll-M a n n and 2/3- 1/3- 1/3*0 G Z w e ig, the q ua rks are p ro po sed a s the basic building Fig. 21.18 blocks of the m e sons and b aryons. A pair of quark and a ntiqu ark m a k e s a m e s o n a n d 3 q u a rk s m a k e a b a ry o n . It is proposed that there are six quarks, the (1 ) up (2 ) d o w n (3 ) strange (4 ) charm (5 ) bottom and, (6 ) top. Th e charges on these q uarks a re fractional a s sho w n in Ta b le 21.5. A proton is assum ed to be m ade up of two up quarks and one dow n quark a s shown in F ig 2 1.1 8 a. T h e neutron is assum ed to be m ade of one up quark a nd two d ow n quarks as shown in Fig. 2 1.1 8 (b ). Currently, the hundrod of hadrons can be a c c o u n te d for in te rm s o f six q u a rk s a n d their a ntiquarks. It is believed that quarks cannot exist on their ow n . their existence h as bee n indirectly verified. CB T h e com bined n um b er of all the protons and neutrons in a n ucleu s is know n a s m ass num ber and is denoted b y A 256

T h e protons and neutrons prosent in tho nucleus are called nucleonsT h e num ber of neutrons present in a nucleus is called its neurons num ber and isdenoted by N.T h e num ber of protons n s id c a nudeus or the number of electrons outside of tho nudeus■scaled the atom c number or the charge number of an atom and is denoted by ZIsotopes a re such n u d e i of an oloment that have tho sam e charge num ber Z . buthave different m ass num ber A .T h e m a s s of the n u d e u s is alw ays loss than tho total m ass of the protons andneutron that make up the nud eus. Th o difference of the two masses is called massdefect T h o missing m a s s is converted to en ergy m the formation of the n u d e u s andis called the binding energy.Th e emission of radiations (u . and y) from elements having charge number Zgreater than 82 is called radioactivity.T h e c h a n g e of an elem ent into a new olomont due to em ission of radiations is calledradioactivo decay. T h e original element is called parent element and the elementformed due to this decay is called daughter elem ent.Half-life of a radioactive elem ent is that period in w hich half of the atom s of the parentelement decay into daughter elementS u c h a reaction in w hich a h eavy n u d e u s like uranium splits up into two nuclei ofequal sizo along with the emission of energy during reaction is called fissionreaction.S u c h a nuclear reaction in w hich two light n u d e i m e rge to form a h eavy nucleusalong with the em ission of e n e rg y is called fusion reactionT h e strength of the radiation source is indicated by its activity m easured inbocquorol. O n e becquerel (B q ) is one disintegration per second .A larger unit is curie(C i) w hich equals 3.7 x 10 Mdisintegrations per secondT h e effect of radiation on a body absorbing it relates to a quantity called absorbeddose D defined as the energy E absorbed from ionizing radiation per unit m ass m ofthe absorbing bodyT h e basic forces are:i. Gravitational force ii. Electrom agnetic forceiii. W e a k n u d e a r force iv. Th o strong forceSubatom ic particles are divided into following three groups:i. Photons ii. Leptons iii. HadronsElem entary partides are the basic building blocks of matter. 257

egm m2 1 .1 W h a t a re Isotopes? W h a t d o they havo in c o m m o n a nd w hat are thetr differences?2 1 .221.3 W h y are h o a vy nuclei unstable?21.4 If a n u c le u s h a s a half-life o f 1 y e a r, d o e s this m e a n that it w ill b e c o m p le te ly d ecayed after 2 ye ars? Explain. W h at fraction of a radioactive sam ple decays after two half-lives h ave elapsed?2 1 .5 T h e rad ioa ctive ole m e n t 7J jR a h a s a half-life o f 1 .6 x 10* y e a rs . S in c e th e E a rth is2 1 .6 a b o u t 5 billion y e a rs o ld . h o w c a n y o u e xp la in w h y w e still c a n find this e lem ent in nature? D escribe a brief account of interaction of various typos of radiations with matter.21.7 Explain h o w a and p -pa rtid es m a y ion ize an atom w ithout directly hitting the e lectrons? W h a t is the difference in the action of the two particles for producing ionization?2 1.8 A particlo w h ich pro duces m ore ionization is less penetrating. W h y ?2 1.9 W hat information is revealed b y the length and shape of the tracks of an incident particle in W ilso n cloud c h a m b e r?2 1 .1 0 W h y m u st a G e ig e r M u ller tu b e for d e te ctin g a -p a r tid e s h a v e a v e ry thin e n d w indow ? W h y d oos a G e iger Muller tube for detecting y-rays not need a w indow at all?21.11 D e s c rib e th e principle o f o p e ra tio n o f a solid state d ete cto r o f io n izin g radiation in term s of generation and detection o f chargo carriers.2 1.12 W h at d o w e m ean b y the term cntical m a ss?2 1.1 3 D iscuss the advantages and d isadvantages of nuclear pow er com pared to the use of fossil fuel generatod power.21.1 4 W h a t factors m a ke a fusion reaction difficult to a ch ieve?2 1 .1 5 D is cu ss the a dvan tag es and d isad va n ta g es of fission pow er from the point of2 1 .1 6 safety, pollution and rosources21 17 W h a t d o yo u understand b y 'b a ck g ro u n d rad iation '? State tw o so u rce s of this radiation. If s o m e o n e a ccid en tfy s w a llo w s a n a -s o u r c e a n d a p -s o u rc e w hich would be the m ore dangerous to him ? Explain w hy?2 1.1 8 W h ich radiation d ose w ould deposit m ore e n e rg y to the b o d y (a ) 10 m G y to the hand, o r (b ) 1 m G y dose to the entire body.2 1.19 W h a t is a radioactive tracer? D escribe o ne application e ach in m edicine, agriculture and industry.2 1.2 0 H o w c a n radioactivity help in the treatm ent of can ce r? 258

essssm21.1 Find the m a ss defect a n d the binding e n e rgy for tritium, if the a tom ic m a ss of tritium2 1 .22 1 .3 is 3.016049 u (A n s : 0.00857 u. 7.97 M eV)21.4 Thehalf-lifeof’ JSris9.70hours.Fioditsdecayconstant. (A n s : 1.99 x 1 0 ’ s) T h e elem ent** P a is unstable a nd de c a ys b y ^-em ission with a half-life 6 .6 6 hours, state the n udear reaction and the daughter nuclei. (A n s: * U) Find the energy associated with the following reaction: (M ass of ',H=1.00784 u) * }N + ,H e --------- > ” 0 + ',H W hat does negative sign indicate? (A n s : 1.12 M eV )2 1 .5 Determ ine the energy associated with the following reaction: (m ass of “ C=14.0077u) ’J C --------- » ’ j N + °e (A n s : 3.77 M eV)2 1.6 If decays twice by a-em ission. w hat is tho resulting isotope? (A n s :^ jR n )2 1.7 C alculate the e n e rg y (m M e V ) released in the following fusion re a ctio n ; * H + * H --------- ► j H e + ^ n (A n s : 17.6 MeV/event)2 1 .8 A sheet of lead 5.0 m m thick reduces the intensity of a beam of r-ra y s by a factor 0.4. F ind half value thickness of lead sheet w hich will reduce the intensity to half of its initial value. (A n s : 3.79 m m )2 1 .9 R adiation from a point source o b eys the Inverse square law. If the count rate at a distance of 1.0 m from G e ig e r counter is 3 6 0 counts p er minute, w h at will be its count rate at 3.0 m from the source? (A n s : 40 counts per m in.)21.10 A 75 kg person receives a whole b ody radiation dose of 24 m -ra d. delivered by a -p a rlid e s for w hich R B E factor is 12. C alculate (a ) the a bso rbe d e n e rg y in Joules, and (b ) the equivalent d ose in rem. [A n s : (a ) 18 m J (b ) 0.29 rem)N o te : C o n s u lt the table o n p a g e 222, w h e re re q u ire d , fo r a to m ic m a sse s. 259

CW HJJik'J> A lte rna ting C u rre n t Current produced by a voltage source whose polarity keeps on reversing with time> Am orphous Those solids in which arrangement of atoms or> A m p lifie r motoculos aro not regular signal A device that increases the output of electrical> A tom ic N um ber> B inding Energy fed as input Th e number of protons in the nucleus> B lack B o dy> Bulk M odulus Th e work done on the nucleus to separate it into its> Capacitor> Cathode ray constituent neutrons and protons A body that absorbs all tho radiations incident upon it O scilloscope> C o m p to n effect Ratio of applied stress to volumetric strain> C rystalline Solids A dovicc that can store charge> Current High speed graph plotting device G e n e ra to r A n increase in the wavelength of X-rays when> Digital S ystem scattered by bound electrons Substances having regular arrangement of atoms or> Elastic lim it ii> Electric C u rren t molecules> Electric Field A device which converts mechanical energy into electrical energy In te n s ity It deals with only those quantities which have only two discrete values Th e limit beyond which the sample becomes permanently deformed Rate of flow of electric charge Electric field force per unit charge at a point 260

r Electric Flux N u m b e r of electric field lines passing through certain surface element> Electric Potential Am ount of wort; done in bringing a unit positive charge from infinity to a point> Electrolysis Conduction of electricity due to chemical reaction in liquids> Electrom agnetic W a v e s w hich d o not require an y medium for their W aves propagation> Electrom otivo A measure of tho energy supplied by a source ofForce electric current per unit chargeElectron volt Unit of en ergy equals to 1.6*1 0'1#JElectroplating Electric metallic coating> Forw ard Bias Bias vo ltage w hich w h e n applied to a p - n junction produce large curron* flow> Frequency N um ber of cy c le s per unit timeFusion S uch nuclear reaction in which tw o bght nuclei m erge to form a h e a vy nucleus with tho emission of energy> H alf life It is the period in w hich half of the radioactive element atoms decay> Holography A method of recording three dimensional image> Impedance Com bined effect of resistances and reactances in an A C . circuit> Inductance T h e phenom enon in which changing current in a coil produces an om f in itself> Inertial fram e of Coordinate system in which the law of inertia is valid reference> Insulators A material w ith a very high electrical resistivityIonization Potential Th e energy needed to remove the electron from an atom o r m olecule to infinite distance 261

Laser Light amplification by stimulated emission of radiationLo gic Gate Electronic circuits which implements various logic operations> M agnetic Indu ctio n Magnetization of a substance by an external magnetic field> M ass Defect It is the difference betw een tho m ass of the separated nucleons and the com bined m ass of the nucleus> Mass Number Total num ber of protons and neutrons in a nucleus> M odulation T h e process of com bining the low frequency signal with a high frequency radio w ave> M utual Ind u cta n ce A phenom enon in which a changing current in one cod> NAVASTAR produces em f in other coil Navigation system based on Einstein theory of relativity> Nuclear Energy E nergy derived from nuclear reactions either by fission or b y fusion> Nuclear fission Disintegration of atom ic nucleus into two or more> Nuclear Reactor fragments with tho em ission of huge am ount of energy A device in which controlled nuclear fission reaction takes place> Nucleons Protons and neutron in the nucleus.> Pair Production Production of cloctron-position pair from a photon> P ho to voltaic cell A device that detects or m easures electromagnetic radiation b y generating a potential at a junction> Photodiode A device used to delect light falling on it> Photoelectric Em ission of electrons from metallic surface whenEffect exposed to electromagnetic radiations> P lastic deform ation A permanent deformation of a solid object to an applied stress 262

P olym eric Solids T h e solid m aterials with a structure that is intermediate between ordered and disordered structure> Rectification Conversion of alternating current into direct current> R esistivity Tendency of material to oppose the flow of current> R e v c rs o B ia s Bias voltage which w hen applied to a p - n junction produces a very sm all or n o current flow> Spectrograph A n instrument for producing photographic record of spectrum> Spectroscopy T h e investigation of w a ve le n gth and intensities of electrom agnetic radiations emitted or absorbed by the> Strain atoms Th e change produced in the size or shape of the body> Stress by applying a stress> Super Conductors Force per unit area Th o se material whose resistivity becom os zoro below> Therm istor a critical temperature> Tim e Period Heat sensitivo resistor Th a t interval during w hich the voltage source changes> Transform er its polanty once A device which converts high A C . voltage to low A . C .> Transistor voltage or low A .C . voltage to high A . C . voltage Sem i conducting m aterial to which at least three> Ultim ate tensile electrical contacts are m ad e stress T h e m axim um stress that a material can withstand> Yo un g's M odulus Ratio of the tensile stress applied to the material to the resulting tensile strain 263

EEm gp1. Colle ge P hysic b y H arris Benson.2. Physics for Scientist and Engineers by R aym ond A . Serway3. Physics Concepts and Applications by Je rry Wilson.4. T h e Ideas of P hysics b y D oug la s G Giancofa.5. Conceptual Physics by Paul G Hewitt.6. College Physic by Robert. l.W eb er.7. Cam bridge Physics by Jones and Marchington.8. Principles of Physics by F.J. Buecho and D avid A . Jcrde.9. Fundam entals of Physics b y David Holliday. Robert Resnik and Jeart Walker.10. A d va n c e d P h ysics b y Jo n a th a n Ling.11. Colle ge P h ysics b y S e a rs . Z e m a n s k y a n d Young.12. Fundam entals of College Physics by Peter J Nolan.13. Physics by Robert Hutchings.14. Nuffield P h ysic s b y Geoffery Dorling.15. A d va n ce d level P h ysic s b y Nelkon a nd Parker.16. A d va n ce d P h ysic s b y T. D u n ca n.17. Understanding P h ysic s b y Poplo.18. Fundamental of Physics by Tahir Hussain.19. Physics for A dvanced Level by Jim Breithhaupt.20. C olle ge P h ysics b y Vincent P. Coietta.21. Physics by J.B . Marion22. P h ysics b y Ata'm P. A rya .23. Contem porary College Physics by E . R. Jo n es and R . L. Childers24. Physics by John D . Cutnetl and Kenneth W . Johnson.25. Physics by Kane and Stemhcin. 264

A 9 7-9 9 C a p a cita n ce 22 A C . generator 250 C a p a cito r 22 Absorbed dose 226 CAT Scanar 211 A lpha panicles t il C h n ra c teristic X -ra ys 2 0 9 -2 1 0 Alternating current 74 Choko 123 Am m eter 136 C o lle cto r 159 6 1-6 2 1 6 6 -1 6 7 A m o rp h o u s solid . 131 Com pa rator 138 A m p e re 's law 168 C o m p ro s s io n n l stress 138 Am plitude m odulation 168 C o m p r o s s iv c Strom ’ 90-191 A N D gate 1 9 2 -1 9 3 C o m p to n effect 1 9 0 -1 9 1 A N D O peration 220 C o m p to n shift 1 9 0 -1 9 1Annihilation ot m atter 220 C o m p to n w avolcngth 38 Atom ic n u d e u s 76 143 Atom ic num ber C o n d u c ta n c e 1 4 3 -1 4 4 Avom oter 203 C o n d u c tio n b an d 32 256 C on d uctors 244C 159 C o n v e n tio n a l current 150B a im e r series 2 5 4 -2 5 5 C o ro 249B a ryo n s . 250 C o rc siw ity 2Base 226 C o s m ic rad iation 2 4 2 -2 4 3Basic torccs 223 146Bocgucrai 183 C o u lo m b 's la w 136Beta partides 1 8 2 -1 8 3 Critical m a s s 250Bm dm g energy 2 0 4 -2 0 5 Critical te m p o ra tu ro 160Black body 205 C rys ta llin e s o lid -Black b o d y radiation 168 C u rie 1 0 0 -1 0 1B o h r's atom ic m odel 204 C u rre n t gain 102B o h r's orbit D 230B oolea n variable 1 9 4 -1 9 5 D C . g e n e iu iv^i 74B racken series 210 140 O .C . m o to r 193B ra g g 's equation 2 55 -25 6 D a u g h te r e le m e n t 230Brom sstrahJung 139 Dead b e a t galva no m eter ‘ 154Bhnio substances 221B uilding btoek o l m atter 6 8 -7 0 d e -B ro g lie rota tio n 221Bulk m odulus Decay co n sta n t 148C D e p e lo tio n re g io nC .R .O . Dcuteri u m D eu tro n D ia m a g n e tic su b sta n ce s 265

Dielectric constant 24 G 164-165Digital multimeter Gam 71-74 77-78 .2 2 6 -2 2 7Digital system 167-168 G a lva n o m e te rD o m ains 148-149 Gam m a rays 235-237 G oigcr Muller counterDuctilo substancor. 140E G eneral thoory of relativity 178o.m.f. 43-44 Gray 251 G uass's law 12Emstom photo etoctnc equation 188 HElastic deformation 140Electric current 32 Hadrons 2S6Electric field strength 7 Half life 229Electric flux 9-10 Half w avo rectification 156Etoctnc intensityEtoctnc polarization 5 H e -N o laser 215Eloctric potontial 24-25 Honery 92-94Electrom ag net 15 Holography 149 216Electromagnetic spectrumEloctromagnotic waves 185 Hooko's law 140Electron microscope 128-129Electron volt 197 Hydrogen emission spectrum 207-208Emittor 19 Hysteresis 150Energy band theory Hysteresis loop 148-150Enorgy dens.ty 159 150E n e rg y -m a s s relation 143-144 : iHysteresisflossEquivalent dose 96 Impcdanco 120Excitation potontial Induced current 82-84 180-181 251 Induced e.m.f. 82-84 207 177 Inertial framo of reference 143-144FExtrinsic semiconductor 144 Insulators 144 Intrinsic sem iconductorFarad lomzation energy 207 22 Ionization potential 207Faraday’s law 87 Isotopos 221Fast reactor 246 KFerromagnetic materials 148Fission chain reaction Kirchhoffs first law 46 242 47Fluorescence 233 Kirchhoffs second lawForbidden er ergy gap 143 LForward resiitanco 155 177 Laser 213Fram e of referenco Leakago current 155Frequency modulation 131-132 Length contraction 179Full w avo rectification 157Fussion reaction 247 Le n z's law 88 Leptons 256 U g ht emitting diode 157 266

ficlative bological effectiveness 2 5 1 T Ten sile strainRelative motion 177 138 Tensile stress 138Rem 251 Therm al reactor 246 Th e rm isto r 42Resistivity 38 Threshold frequency 188 Tim o dilation 179Rcsonanco 125 Tracer techniques 252-253Rctantivity 150 Transformer 103-106 159Rheostat <11 Transistor 221 TritiumRight hand rule 57 140 U 197-199R uthe^o'd atomic model 220 Ultimate tensile strength 220Rydberg constant 2 0 3 .2 0 8 Unccdam ty prmoplo 216-216 Unified massS Usos of loser 101-162 V 75Saturation 150 Voltage gam 138-139 VoltmeterSett inductance 93 Volum etric strain 195-196 60Self quenching 236 W 50-51 W a ve particle duawy 234-235Semiconductors 143 Weber 188 W healstone bridgeSensors 170-171 Wilson cloud chamber 8-9 W ork function 170Shear modulus 139 170Shear strain 139 X 169-170 138 Xerography 169Shear stress 209-211 X N O R galeSieved 251 X N O R operation 139 X O R gateSolid state detector 237 X O R operation X-raysSpecial theory of relativity 178-181 YSpeclrafseries 203 Young's modulusSpectroscopy 202Step down transformer 104Step up transformer 104Stephan Boltzm ann's law 184S tephan’s constant 184Stimulated absorption 213Stimulated emission 213Stopping potential 187Strain 138Stress 138Strcssstrain curvo 140Superconductor 146-147 26X

Linear absorption co-efficient 233 Operational amplifier 162-163 O R gate 168Lym an series 203 O R operation •168M P 154 p - n junction 192Magnetic dipole 148 Pair production 227 Parent element 204Magnetic flux 60 Paschen series 204 Pfund series 158Magnetic flux density 60-61 Photo diode 187 Photo electron 187M ass defect 223 Photo electron 158 189M ass spectrograph 222-223 Photo voltaic cell 187-189 Photocell 185M a ss variation 180 184 Photoelectric effect 140M easurem ent ot e/m 66-67 Photon 140 136-137Mesons 256 Plancks constant 214 Plastic deformation 192Miliikan's method 20-21 Plasticity 51-52 Polym eric solids 204Moderator 244 Population inversion 140 Positron 221Modulation 131 Potentiometer Principle quantum number 206Modutus of elasticity 139 Proportional limit 206 Protium 256Motional e.m.f. 84 Q 251Mutual inductance 90-91 Quantized energy 234-237 Q uan tized radii 249-250N Quarks 251 •N A N D gate 169 n 227 226N A N D operation 169 Radiation absorbed doso 226 Radiation detector 254N A V A S T A R Navigation system 180 156 Radiation exposureN A V A S TA R 180 Radiation sickness Radioactive decayNight switch 171 Radioactive elements RadioactivityNonmtertval frame of reference 178 Radiography RectificationN O R gate 169N O R operation 169N O T gate 169N O T operation 169n -p -n transistor 159N uclear fission 240Nucloar pow er station 243-245Nuclear reaction 238-239Nuclear reactor 243-246Nuclear transmutation 227-228Nucleon number 2200 37OhmO h m meter 76-77O h m 's law 36O pen loop gain 163 267