2. An electron emitted in beta radiation originates from:
(A) inner orbits of atom
(B) free electrons existing in the nuclei
(C) decay of a neutron in a nuclei
(D) photon escaping from the nucleus
Multiple Choice
ID- 15532
3. Order of magnitude of density of uranium nucleus is:
(A) 10$^{20}$ kg m$^{-5}$
(B) 10$^{17}$ kg m$^{-3}$
(C) 10$^{13}$ kg m$^{-3}$
(D) 10$^{11}$ kg m$^{-3}$
Multiple Choice
ID- 15533
4. The half life of a radioactive substance is 20 s, the time taken for the sample to decay by $7/8^{th}$ of its initial value is:
(A) 20 s
(B) 40 s
(C) 60 s
(D) 80 s
Multiple Choice
ID- 15534
5. Radon has 3.8 days as its half-life. How much radon will be left out of 15 mg mass after 38 days.
(A) 1.05 mg
(B) 0.015 mg
(C) 0.231 mg
(D) 0.50 mg
Multiple Choice
ID- 15535
6. Which of the following cannot be emitted by radioactive substances during their decay?
(A) Neutrons
(B) Protons
(C) Electrons
(D) Helium nuclei
Multiple Choice
ID- 15536
7. The half life of a radioactive substance is 30 days. What is the time taken to distintegrate to $3/4^{th}$ of its original mass?
(A) 30 days
(B) 15 days
(C) 60 days
(D) 90 days
Multiple Choice
ID- 15537
8. How much mass has to be converted into energy to produce electric power of 500 MW for one hour?
(A) 2 × 10$^{-5}$ kg
(B) 1 × 10$^{-5}$ kg
(C) 3 × 10$^{-5}$ kg
(D) 4 × 10$^{-5}$ kg
Multiple Choice
ID- 15538
9. The half life of polonium is 140 days. In what time will 15 g of polonium be disintegrated out of its initial mass of 16 g?
(A) 230 days
(B) 560 days
(C) 730 days
(D) 160 days
Multiple Choice
ID- 15539
10. In a sample of radioactive material, what fraction of the initial number of active nuclei will remain undisintegrated after half of the half life of the sample?
(A) $\frac{1}{4}$
(B) $\frac{1}{2\sqrt{2}}$
(C) $\frac{1}{\sqrt{2}}$
(D) $\sqrt{2} - 1$
Multiple Choice
ID- 15540
11. The set which represents the isotope, isobar and isotone respectively is:
(A) $\ce{(^{2}_{1}H, ^{3}_{1}H), (^{197}_{70}Au, ^{199}_{80}Hg) and (^{3}_{2}He, ^{2}_{1}H)}$
(B) $\ce{(^{3}_{2}He, ^{1}_{1}H), (^{197}_{79}Au, ^{198}_{80}Hg) and (^{1}_{1}H, ^{3}_{1}H)}$
(C) $\ce{(^{3}_{2}He, ^{3}_{1}H), (^{2}_{1}H, ^{3}_{1}H) and (^{197}_{79}Au, ^{198}_{80}Hg)}$
(D) $\ce{(^{2}_{1}H, ^{3}_{1}H), (^{3}_{2}He, ^{3}_{1}H) and (^{197}_{79}Au, ^{198}_{80}Hg)}$
Multiple Choice
ID- 15541
12. The natural boron of atomic weight 10.81 is found to have two isotopes $^{10}$B and $^{11}$B. The ratio of abundance of isotopes of natural boron should be:
(A) 11 : 10
(B) 81 : 19
(C) 10 : 11
(D) 19 : 81
Multiple Choice
ID- 15542
13. Two nuclei have their mass numbers in the ratio of 1 : 3. The ratio of their nuclear densities would be:
(A) (3)$^{1/3}$ : 1
(B) 1 : 1
(C) 1 : 3
(D) 3 : 1
Multiple Choice
ID- 15543
14. A 280 day old radioactive substance shows an activity of 6000 dps. 140 days later its activity becomes 3000 dps. What was its initial activity?
(A) 20000 dps
(B) 24000 dps
(C) 12000 dps
(D) 6000 dps
Multiple Choice
ID- 15544
15. Fast neutrons can easily be slowed down by:
(A) the use of lead shielding
(B) passing them through water
(C) elastic collisions with heavy nuclei
(D) applying a strong electric field
Multiple Choice
ID- 15545
16. Complete the series $\ce{^{6}H_e \rightarrow e^{+} + ^{6}Li^{+}}$:
(A) neutrino
(B) antineutrino
(C) proton
(D) neutron
Multiple Choice
ID- 15546
17. Light energy emitted by star is due to:
(A) breaking of nuclei
(B) joining of nuclei
(C) burning of nuclei
(D) reflection of solar light
Multiple Choice
ID- 15572
18. In nuclear reaction, there is conversation of:
(A) mass only
(B) energy only
(C) momentum only
(D) mass, energy and momentum
Multiple Choice
ID- 15573
19. Carbon dating is the best suited determining the age of fossils, if their age in years is of the order of:
(A) $10^{3}$
(B) $10^{4}$
(C) $10^{5}$
(D) $10^{6}$
Multiple Choice
ID- 15574
20. The half life of radioactive radon is 3.8 days. The time at the end of which $(1/20)^{th}$ of the radon sample will remain undecayed $(\text{Given } log_{10}e = 0.4343)$ is:
(A) 3.8 days
(B) 16.5 days
(C) 33 days
(D) 76 days
Multiple Choice
ID- 15575
21. The half life period of a radioactive element $X$ is same as the mean life time of another radioactive element $Y$. Initially, they have the same number of atoms. Then:
(A) $X$ and $Y$ decay at same rate always
(B) $X$ will decay faster than $Y$
(C) $Y$ will decay faster than $X$
(D) $X$ and $Y$ have same decay rate initially
Multiple Choice
ID- 15576
22. If the binding energy per nucleon of deuterium is 1.115 MeV, its mass defect in atomic mass unit is:
(A) 0.0048
(B) 0.0024
(C) 0.0012
(D) 0.0006
Multiple Choice
ID- 15577
23. Pick up the incorrect statement for the nucleus from the following:
(A) $β^-$ emission from the nucleus is always accompanied with a neutrino
(B) The energy of the $α$-particle emitted from a given nucleus is always constant
(C) $γ$-ray emission makes the nucleus more stable
(D) Nuclear force is charge-independent
Multiple Choice
ID- 15578
24. The radius of a spherical nucleus as measured by electron scattering is 3.6 fm. What is the mass number of the nucleus most likely to be?
(A) 27
(B) 40
(C) 56
(D) 120
Multiple Choice
ID- 15579
25. If in a nuclear fusion reaction, mass defect is 0.3%, then energy released in fusion of 1 kg mass:
(A) $\ce{27\, × 10^{10} J}$
(B) $\ce{27\, × 10^{11} J}$
(C) $\ce{27\, × 10^{12} J}$
(D) $\ce{27\, × 10^{13} J}$
Multiple Choice
ID- 15580
26. The radio of the nuclear radii of the gold isotope $\ce{^{197}_{79}Au}$ and silver isotope $\ce{^{107}_{47}Ag}$ is:
(A) 1.23
(B) 0.216
(C) 2.13
(D) 3.46
Multiple Choice
ID- 15582
27. When a nucleus is an atom undergoes a radioactive decay, the electronic energy levels of the atom:
(A) do not change for any type of radioactivity
(B) change for α and β radioactivity but not for γ-radioactivity
(C) change for α-radioactivity but not for others
(D) change for β-radioactivity but not for others
Multiple Choice
ID- 15600
28. A radioactive decay can form an isotope of the original nucleus with the emission of particles:
(A) one α and four β
(B) one α and two β
(C) one α and one β
(D) four α and one β
Multiple Choice
ID- 15601
29. Fission of nuclei is possible because of the binding energy per nucleon in them:
(A) increases with mass number at low mass numbers
(B) decreases with mass number at low mass numbers
(C) increases with mass number at high mass numbers
(D) decreases with mass number at high mass numbers
Multiple Choice
ID- 15602
30. The number of β-particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an:
(A) isomer of parent
(B) isotone of parent
(C) isotope of parent
(D) isobar of parent
Multiple Choice
ID- 15603
31. During negative β decay, an antineutrino is also emitted along with the emitted electron. Then,
(A) only linear momentum will be conserved
(B) total linear momentum and total angular momentum but not total energy will be conserved
(C) total linear momentum and total energy but not total angular momentum will be conserved
(D) total linear momentum, total angular momentum and total energy will be conserved
Multiple Choice
ID- 15604
32. Plutonium decays with a half-life of 24000 years. If plutonium is stored for 72000 years, the fraction of it that remains is:
(A) 1/8
(B) 1/3
(C) 1/4
(D) 1/2
Multiple Choice
ID- 15605
33. In nuclear reactors, the control rods are made of:
(A) cadmium
(B) graphite
(C) krypton
(D) plutonium
Multiple Choice
ID- 15606
34. Nuclear force is:
(A) strong, short range and charge independent force
(B) charge independent, attractive and long range force
(C) strong, charge dependent and short range attractive force
(D) long range, change dependent and attractive force
Multiple Choice
ID- 15607
35. If radioactive nuclei emit $\beta$-particle, then mass-number:
(A) increases by 1 unit
(B) decreases by 1 unit
(C) increases by 2 unit
(D) decreases by 2 unit
Multiple Choice
ID- 15608
36. An alpha particle is emitted from $\ce{_{88}Ra^{226}}$, then the product nuclei have:
(A) Z = 84, A = 224
(B) Z = 86, A = 224
(C) Z = 86, A = 222
(D) Z = 82, A = 222
Multiple Choice
ID- 15609
37. $X$-ray was discovered by:
(A) Becqueral
(B) Marie curie
(C) Roengton
(D) Vanlaw
Multiple Choice
ID- 15610
38. Fusion takes place at high temperatures because:
(A) Atom are ionised at high temperature
(B) Molecules break up at high temperature
(C) Nuclei break up at high temperature
(D) Kinetic energy is high enough to overcome repulsion between nuclei
Multiple Choice
ID- 15611
39. The order of nuclear density is:
(A) $10^{3}$
(B) $10^{17}$
(C) $10^{6}$
(D) None
Multiple Choice
ID- 15612
BSEB, 2018 (C)
40. If $R$ is the radius and $A$ is the mass of a nucleus then the graph of $\ce{log R}$ versus $\ce{log A}$ will be:
(A) A straight line
(B) A parabola
(C) An Ellipse
(D) None of these
Multiple Choice
ID- 15613
BSEB, 2017 (A), 2019 (A)
41. The time in which a radioactive substance becomes half of its initial amount is called:
(A) average life
(B) half-life
(C) time-period
(D) decay constant
Multiple Choice
ID- 15614
42. Mass is converted into energy according to the relation:
(A) $\ce{E = mc^2}$
(B) $\ce{E = mgh}$
(C) $\ce{E = \frac{1}{2}mc^{2}}$
(D) $\ce{E = \frac{mgh}{c^{2}}}$
Multiple Choice
ID- 15615
43. The helium atom does not contain:
(A) two protons
(B) two electrons
(C) two neutrons
(D) six nucleons
Multiple Choice
ID- 15616
44. The more readily fissionable isotope of uranium has an atomic mass of:
(A) 234
(B) 235
(C) 236
(D) 238
Multiple Choice
ID- 15617
45. The energy of an electron in the 1st orbit of the H-atom is:
(A) -13.6 MeV
(B) -13.6 eV
(C) -13.6 J
(D) 13.6 J
Multiple Choice
ID- 15618
46. The mass no. of a nucleus is M and it's atomic no. is Z. The number of neutrons in the nucleus is:
(A) M - Z
(B) M
(C) Z
(D) M + Z
Multiple Choice
ID- 15619
47. The phenomenon of radioactivity is:
(A) Exothermic change with increase or decrease with temperature
(B) increase on applied pressure
(C) nuclear process does not depend on external factors
(D) None of these
Multiple Choice
ID- 15620
48. When 1 gm of mass is converted into energy, it is equal to:
(A) $\ce{10^{3} \text{kWh}}$
(B) $\ce{10^{9} \text{kWh}}$
(C) $\ce{10^{10} \text{kWh}}$
(D) $\ce{10^{11} \text{kWh}}$
Multiple Choice
ID- 15621
49. A nucleus $\ce{^{12}_{6}C}$ absorbs an energetic neutron and emits a $\beta$-particle the resulting nucleus is:
(A) $\ce{^{14}_{7}N}$
(B) $\ce{^{13}_{7}N}$
(C) $\ce{^{13}_{6}C}$
(D) $\ce{^{12}_{5}B}$
Multiple Choice
ID- 15622
50. By emission of which of the following element remains unchanged:
(A) $\alpha$-decay
(B) $\beta^{+}$-decay
(C) $\beta$-decay
(D) $\gamma$-decay
Multiple Choice
ID- 15623
51. The average binding energy of a nucleon inside an atomic nucleus is about:
(A) 8 eV
(B) 8 MeV
(C) 8 J
(D) 8 ergs
Multiple Choice
ID- 15624
52. In the following reaction, $y$ is : $\ce{_{3}Li^{7} + _{1}H^{1} + _{2}He^{4} + y}$
(A) $\ce{_{2}He^{4}}$
(B) $\ce{_{0}n^{1}}$
(C) $\ce{_{1}D^{2}}$
(D) $\ce{_{1}H^{3}}$
Multiple Choice
ID- 15625
53. $\ce{_{5}B^{10}}$ is bombarded with neutrons so that an alpha particle is emitted. The residual nucleus is:
(A) $\ce{_{3}Li^{7}}$
(B) $\ce{_{1}D^{2}}$
(C) $\ce{_{1}H^{3}}$
(D) $\ce{_{0}n^{1}}$
Multiple Choice
ID- 15626
54. A radioactive element $\ce{_{90}X^{238}}$ decays into $\ce{_{83}Y^{222}}$. The number of $\beta$-particles emitted are:
(A) 6
(B) 4
(C) 2
(D) 1
Multiple Choice
ID- 15627
55. For stability of any nucleus:
(A) B.E. (Binding Energy) per nucleon will be higher
(B) B.E. (Binding Energy) per nucleon will be less
(C) no. of electrons will be more
(D) None of these
Multiple Choice
ID- 15628
56. Packing fraction for a nucleus is given as:
(A) $\frac{M - A}{A}$
(B) $\frac{M + A}{A}$
(C) $\frac{M}{A}$
(D) $\frac{A}{M}$
Multiple Choice
ID- 15629
57. Who discovered heavy Hydrogen?
(A) Uray
(B) Thomson
(C) Mosley
(D) Fermi
Multiple Choice
ID- 15630
58. The frequency of revolution of the electron in the first stationary orbit of the H-atom is:
(A) $\ce{6.57 × 10^{12} Hz}$
(B) $\ce{6.57 × 10^{13} Hz}$
(C) $\ce{6.57 × 10^{14} Hz}$
(D) $\ce{6.57 × 10^{15} Hz}$
Multiple Choice
ID- 15631
59. What percentage of the original radioactive atom is left after four half-lives?
(A) 6%
(B) 10%
(C) 20%
(D) 25%
Multiple Choice
ID- 15632
60. Which of the following is not a mode of radioactive decay?
(A) positron emission
(B) electron capture
(C) fusion
(D) alpha decay
Multiple Choice
ID- 15633
61. The most suitable element for nuclear fission is the element with atomic mass near:
(A) 11
(B) 21
(C) 52
(D) 92
Multiple Choice
ID- 15634
62. With increasing quantum number, the energy differences between adjacent energy levels in atoms:
(A) increases
(B) decreases
(C) remains constant
(D) first increases then decreases
Multiple Choice
ID- 15635
BSEB, 2017 (A)
63. $\beta$-rays are reflected in:
(A) Gravitational field
(B) Only in magnetic field
(C) Only in electrical field
(D) In magnetic and electric field both
Multiple Choice
ID- 15636
BSEB, 2017 (A)
64. Which one of the following is a charge less particle?
(A) Alpha particle
(B) Beta particle
(C) Photon
(D) Neutron
Multiple Choice
ID- 15637
BSEB, 2018 (A)
65. The number of Photons of frequency $10^{14}$ Hz in the radiation of 6.62 J will be:
(A) $10^{10}$
(B) $10^{15}$
(C) $10^{20}$
(D) $10^{25}$
Multiple Choice
ID- 15638
BSEB, 2018 (A)
66. The quantities, which remain conserved in a nuclear reaction:
(A) Total Charge
(B) Angular momentum
(C) Linear momentum
(D) All the above
Multiple Choice
ID- 15639
BSEB, 2020 (A)
67. Atomic number decreases with the emission of $\alpha$-particles from the nucleus: