BSC /SEM VI Subject Code:USPH603/ (Nuclear Physics .

BSC /SEM VISubject Code:USPH603/ (Nuclear Physics)Multiple Choice Questionnaires1.The atomic mass unit is defined asa.the mass of a proton.b.the mass of an electron.c.the mass of a hydrogen-1 atom.d.one twelfth the mass of a carbon-12 atom.2.An element with atomic mass number of 14 and atomic number 6 has how manyneutrons?a.6b.8c.14d.203.Isotopes of an element have nuclei witha.the same number of protons, but different numbers of neutrons.b.the same number of protons, and the same number of neutrons.c.a different number of protons, and a different number of neutrons.d.a different number of protons, and the same number of neutrons.4.If an atom's atomic number is given by Z, its atomic mass by A, and its neutronnumberby N, which of the following is correct?a.N A Zb.N Z-Ac.N A-Zd.None of the above is correct.5.In a {93/41}Nb nucleus, the number of protons, neutrons, and electrons isa.b.c.d.41, 52, 9341, 52, 5241, 52, 4141, 52, 06.The binding energy per nucleona.increases steadily as we go to heavier elements.b.decreases steadily as we go to heavier elements.c.is approximately constant throughout the periodic table, except for very lightnuclei.d.has a maximum near iron in the periodic table.7.An alpha particle is also known as

a.b.c.d.an electron.a positron.a helium nucleus.a photon.8.A beta- particle is also known asa.an electron.b.a positron.c.a helium nucleus.d.a photon.9.The existence of the neutrino was postulated in order to explaina.alpha decay.b.gamma emission.c.beta decay.d.fission.10.When an alpha particle is emitted from an unstable nucleus, the atomic mass numberof the nucleusa.increases by 2.b.decreases by 2.c.increases by 4.d.decreases by 4.e.none of the above.11.If 4.0X1018 atoms decay with a half-life of 2.3 years, how many are remainingafter 3.7 years?a.2.5X1018b.1.7X1018c.1.3X1018d.1.1X101812.A radioactive sample has a half-life of 5.0 min. What fraction of the sample is leftafter 20 min?a.1/2b.1/4c.1/8d.1/1613.The half-life of radioactive iodine-137 is 8.0 days. How many iodine nuclei arenecessary to produce an activity of 1.0 micro-Ci?a.2.9X109

b.c.d.4.6X1093.7X10107.6X101214.What happens to the half-life of a radioactive substance as it decays?a.It remains constant.b.It increases.c.It decreases.d.It could do any of these.15.The mass of {90/38}Sr is 89.907737 u and the mass of the atom its beta decays to is89.907151 u. What is the energy released in the decay?a. 1.2 MeVb. 112 keVc. 0.546 MeVd. 1.8 MeV16. The neutral atoms of all isotopes of the same element contain the same number of.a.b.c.d.neutrons only.ElectronsMass numbersMassesAnswer: (b) Electrons17. The atomic number is not changed by which type of radioactive decay?a.b.c.d.BetaGammaAlphaThe atomic number is affected by all forms of radioactive decayAnswer: (b) Gamma18. Isotopes of an element have a different number ofa.b.c.d.ProtonNeutronElectronatom

Answer: (b) Neutron19. Three types of radioactive elements are emitted when unstable nuclei undergoradioactive decay. Which of the following is not one of thema.b.c.d.BetaGammaAlphadeltaAnswer: (d) delta20. A nuclear fission reaction becoming self-sustaining depends ona.b.c.d.electronsNeutronsEnergyProtonsAnswer: (b) Neutrons21. Helium nuclei particles are calleda.b.c.d.Gamma particlesBeta particlesAlpha particlesNo particles that are helium nucleiAnswer: (c) alpha particles22. When two atomic nuclei combine it is called asa.b.c.d.Chain reactionNuclear fusionNuclear decayNuclear fissionAnswer: (b) Nuclear fusion23. The number of protons or atomic number is reduced to 2 by which form of radioactivedecay?a.b.c.d.Beta-decayGamma decayAlpha decayNone of the aboveAnswer: (c) Alpha decay24. Which statement is true for all three types of radioactive emission?

a.b.c.d.They are deflected by electric fieldsThey ionise gasesThey are completely absorbed by a thin aluminium sheetThey emit lightAnswer: (b) They ionise gases25. A nuclide of the element plutonium 94 Pu 242. What is the number of neutrons in itsnucleus?a.b.c.d.24233614894Answer: (c) 14826. In the Geiger-Nuttall law,radioactive series,, which factor is constant for almost all thea. Rb. BC. Ad.27. 3H is aa. Bosonb. Fermionc. Neutriond. None28. Which statement is truea. Neutrion has zero chargeb. Neutrino has almost zero massc. Neutrino has spin ½d. All of the above29. Electron-capture is associated witha. conversion of a neutron to a proton.b. decrease in mass number by 4 and atomic number by 2.

c. conversion of a proton to a neutron.d. emission of γ rays.a.b.c.d.30. Which of them are atomic models?i. Thomson’s plum puddling modelii. Rutherford’s nuclear modeliii. Bohr’s modeliv. Sommerfeld’s modela. i & iib. i, ii & iiic. ii, iii & ivd. All of these(Ans:d)31. The nucleus consists ofneutronsprotonsneutrons and protonselectrons and neutrons(Ans:c)a.b.c.d.32. Nucleus ispositively chargednegatively chargedneutralcharge keeps on changing(Ans:a)a.b.c.d.33. Proton has the charge1637 times of an electron1737 times of an electron1837 times of an electron1937 times of an electron(Ans:c)a.b.c.d.34. In neutral atom, the electrons are bound to the nucleus byMagnetic forceElectrostatic forceFriction forceCentripetal force(Ans:b)35. The limited number of electrons in ‘M’ shell isa. 2b. 8c. 18

d. 32(Ans:c)a.b.c.d.36. Radioactivity is confined almost entirely to the elements to in the periodic table60, 9283, 10692, 118None of the above(Ans:b)a.b.c.d.37. Which of the following rays are emitted during radioactivity?Alpha-raysBeta-raysGamma-raysAll of the above(Ans:d)a.b.c.d.a.b.c.d.a.b.c.d.a.b.c.d.38. The difference in the mass of the resultant nucleus and the sum of the masses of twoparent nuclear particle is known asmass defectsolid defectweight defectnucleus defect(Ans:a)39. When the nuclei of U235 is splitted into approximately two equal nuclei, the amount ofenergy released per nucleon is0.45 MeV0.9 MeV1.35 MeV1.7 MeV(Ans:b)40. As per radioactive decay law, the small amount of disintegration of the isotope in a smallperiod is equal to–λNλN–2λN2λNWhere λ radioactive decay constant, N number of radioactive nuclei present at any time ‘t’(Ans:a)41. The half life of radioactive nuclei is0.693 / λ0.793 / λ0.693λ0.793λ

Where λ radioactive decay constant(Ans:a)a.b.c.d.42. The average (mean) life for particle decay is1.145 times greater than half life1.245 times greater than half life1.345 times greater than half life1.445 times greater than half life(Ans:d)43. An antiproton is an atomic particle that hasa) the mass of a proton and the charge of an electron.b) the mass of an electron and the charge of a proton.c) the mass of a neutron and the charge of a proton.d) the mass of a proton and the charge of a neutron.44. A certain radioactive element has a half-life of 20 d. The time it will take for 7/8 of theatoms originally present to disintegrate isa) 20 db) 40 dc) 60 dd) 80 d45. A conservation law that is not universal but applies only to certain kinds of interactionsis conservation ofa) lepton numberb) baryon numberc) spind)Strangeness46. In quantum electrodynamics (QED), electromagnetic forces are mediated bya) the interaction of electrons.b) hadrons.c) action at a distance.d) the weak nuclear interaction.47. Fission occurs because the average binding energy per nucleon for the fission fragmentsis higher than that for the original nucleus. The change in binding energy per nucleon isapproximatelya) 0.20 MeVb) 1.0 MeVc) 7.0 MeVd) 28 MeV48. When lead-207 (Z 82) is bombarded with neutrons, it can change intoa. lead-208b. lead-206c. tellurium-208 (Z 81)

d. bismuth-208 (Z 83)49.Complete the following nuclear reaction:168O 4He - 19Ne210a. 1pb. 1nc. 2Hd. 3H50. When a target nucleus is bombarded by an appropriate beam of particles, it ispossible to producea. a less massive nucleus, but not a more massive one.b. a more massive nucleus, but not a less massive one.c. a nucleus with smaller atomic number, but not one with a greateratomic number.d. a nucleus with greater atomic number, but not one with a smalleratomic number.51.What is the Q-value of the folllowing reaction?144N He 1p 17O(14.003074) (4.002603) (1.007825) (16.999131)a. 1.191 MeVb. -1.191 MeVc. 1.279X10-3 MeVd. -1.279X10-3 MeV52. What is the energy released (positive) or absorbed (negative) in the followingreaction?3a.b.c.d.3H H 4He 2(1n)(3.016049) (3.016049) (4.002603) (1.008665)0.0122 MeV-0.0122 MeV11.3 MeV-11.3 MeV53. What is the mass of the products of a nuclear fission reaction compared to themass of the original products?a. greaterb. lessc. the samed. varies according to the reaction

54. What is the mass of the products of a nuclear fusion reaction compared to theoriginal elements?a. greaterb. lessc. the samed. varies according to the reaction55. The fuel for nuclear fusion in the center of the Sun isa. Hb. Hec. Ud. any radioactive material56. The fuel for nuclear fission isa. Hb. Hec. Ud. any radioactive material57. In the fission reaction 235U 1n - 141Ba 92Kr neutrons, the number ofneutrons produced isa. zero.b. 1.c. 2.d. 3.58. What is the meaning of the term "critical mass"?a. This refers to the mass of the "critical" elements in a reactor, i.e., theuranium or plutonium.b. This refers to the minimum amount of fissionable material required tosustain a chain reaction.c. This is the amount of mass needed to make a power reactor economicallyfeasible.d. This is the material which is just on the verge of becoming radioactive.59. All of the following are units used to describe radiation dosage in humans excepta. curie.b. rad.c. rem.d. RBE.e. sievert.60. A unit that measures the effective dose of radiation in a human is thea. curie.b. RBE.

c. rad.d. rem.61. The chief hazard of radiation isa. damage to living cells due to ionization.b. damage to cells due to heating.c. damage to living cells due to the creation of chemical impurities.d. the creation of new isotopes within the body.62, An X-ray technician takes an avearge of ten X-rays per day and receives 2.5 mradper X-ray. What is the total dose the technician receives in 250 working days?a. 2.50 remb. 5.00 remc. 6.25 remd. 7.75 rem63. The instrinsic spin of a photon isa. 1b. 0c. ½d. -1/264.Which is not an energy term in Semi Empirical mass formula in Liquid drop modela.Volume Energyb.Surface Energyc.Coulombs Energyd.Nuclear Energy65.Pairing Energy in Liquid drop model is zero fora.Even-Even Nucleib.Odd-Odd Nucleic.Even-Odd Nucleid.All of the above66. The angular frequency of a cyclotron is independent ofa.b.c.d.SpeedMassMagnetic fieldChargeAnswer: (a) Speed67. The maximum kinetic energy of the positive ion in the cyclotron is

a.b.c.d.qBR2/2mq2B2R2/2mq2B2R2/mqBR/mAnswer: (b) q2B2R2/2m68. Cyclotron cannot acceleratea.b.c.d.ElectronsNeutronsPositive ions(Both (1) and (2)Answer: (d) Both (1) and (2)69. The cyclotron frequency of an electron grating in a magnetic field of 1 T is approximatelya.b.c.d.28 MHz280 MHz2.8 GHz28 GHzAnswer: (d) 28 GHz70. Suppose a cyclotron is operated at an oscillator frequency of 12 MHz and a dee radius of53cm. What is the resulting kinetic energy of the deuterons?a.b.c.d.16.6 MeV12 MeV15 MeV14 MeVAnswer: (a) 16.6 MeV71. An alternating electric field of frequency f is applied across the dees (radius R) of acyclotron that is being used to accelerate protons (mass m). The operating magnetic field(B) used in the cyclotron and the kinetic energy (K) of the proton, produced by it, are givenbya.b.c.d.B mf/e and K 2mπ2v2R2B 2πmf/e and K m2πvR2B 2πmf/e and K 2mπ2v2RB mf/e and K m2πvR2Answer: (c) B 2πmf/e and K 2mπ2v2R72. The energy of emergent protons in MeV from a cyclotron having a radius of its dees 2 mand applied magnetic field 0.8 T is (mass of proton 1.67 x 10-27 kg).