Important for All entrance examinations such as NEET (UG), IIT-JEE (Mains), NDA, CUET, AIIMS, IAS etc.
- The neutron was discovered by whom?
a) Marie Curie
b) Pierre Curie
c) Rutherford
d) James Chadwick - Which of the following has the highest neutron ratio?
a) 8O16
b) 2He4
c) 26Fe56
d) 92U235
3. The magnetic moment of a revolving electron around the nucleus varies with the principal quantum number as which of the following?
a) μ ∝ n
b) μ ∝ 1/n
c) μ ∝ n2
d) μ ∝ 1/n2
4. Binding energy curve is almost flat for mass numbers
a) 50-80
b) 1 – 10
c) 50-239
d) 80-120
5. Which of the following nuclei is most stable
a) even-even
b) odd-odd
c) odd-even
d) even-odd
6. Maximum Binding energy per nucleon is for
a) Carbon
b) Iron
c) Helium
d) Neon
7. Fusion reations place at high temp, because
a) Kinetic energy is high enough to overcome repulsion between nuclei.
b) Nuclei break up at high temperature.
c) Atoms are ionised at high temperature.
d) Molecules break up at high temperature.
8. Heavy water is used as a moderator in a nuclear reactor. The function of the moderator is to
a) absorb neutrons and stop chain reaction
b) To cool the reactor
c) To slow down the neutrons to thermal energies.
d) To control the energy released.
9. Which of the following is the best nuclear fuel.
a) Thorium-236
b) Plutonium – 239
c) Neptunium-239
d) Uranium-236.
10. For thorium A = 232 and Z = 90. At the end of some radioactive disintegrations we obtain an isotope of lead with 20882pb. Then the number of emitted α and ß particles are
a) α = 4, ß = 6
b) α = 5, ß = 5
c) α = 6, ß = 4
d) α = 6, ß = 6
11. When the number of nucleons in nuclei increases, the binding energy per nucleon numerically
a) increases continuously with mass number.
b) decreases continuously with mass number.
c) First increases and then decreases with increase of mass number.
d) Remains constant with mass number.
12. The mass number of nucleus having radius equal to half of the radius of nucleus with mass number 192 is :
a) 32
b) 24
c) 60
d) 48
13. A neutron can cause fission in which of the following?
a) Hydrogen
b) Uranium-235
c) Thorium
d) Uranium-238
14. In nuclear reactors, what are the controlling rods made of?
a) Cadmium
b) Graphite
c) Stainless steel
d) Plutonium
15. Which of the following is used as a moderator in a nuclear reactor?
a) Cadmium
b) Plutonium
c) Uranium
d) Heavy water
16. Nuclear fusion is possible in which of the following cases?
a) Only between light nuclei
b) Only between heavy nuclei
c) Between both light and heavy nuclei
d) Only between nuclei, which are stable against decay
17. In a nuclear reaction, there is the conservation of which of the following?
a) Mass only
b) Energy only
c) Momentum only
d) Mass, energy, and momentum
18. What amount of energy is released by deuterium and tritium fusion?
a) 60.6 eV
b) 12.6 eV
c) 17.6 eV
d) 28.33 eV
19. What is the reaction responsible for the production of light energy from the sun?
a) Fusion
b) Fission
c) Nuclear
d) Emission
20. Which of the following is an essential requirement for initiating the fusion reaction?
a) Critical mass
b) Thermal neutrons
c) High temperature
d) Critical temperature
21. What is the energy released in the fission of 2 kg of Uranium 235? (Given: energy per fission = 200 MeV)
a) 1.64 × 1014 J
b) 1.64 × 1015 J
c) 2.64 × 1014 J
d) 1.64 × 1020 J
22. Why is a fusion reaction difficult to perform?
a) The nuclei are set up far from each other
b) The attraction between the nuclei
c) Sun’s energy is not sufficient
d) Repulsion between the nuclei
23. Which of the following forms the basis of a nuclear reactor?
a) Uncontrolled chain reaction
b) Fast nuclear reaction
c) Controlled chain reaction
d) Catalyst controlled nuclear reaction
24. Uranium 235 mass should be greater than X, then it is capable of continuous fission by itself. Identify X.
a) Critical size
b) Threshold point
c) Critical shape
d) Specific size
25. Which of the following is the main result of nuclear fission?
a) Helium
b) Strontium
c) Krypton
d) Barium
26. Find the true statement.
a) Nuclear charge is dependent on the charge
b) The nuclear force is weaker than the electromagnetic force
c) The nuclear force is independent of charge
d) The nuclear force is weaker than the gravitational force
27. Which of the following best define nuclear forces?
a) The attraction between protons and neutrons
b) Repulsion between protons and neutrons
c) The attraction between protons and electrons
d) The attraction between electrons and neutrons
28. A nucleus at rest splits into two nuclear parts having radii in the ratio of 1:3. Find the ratio of their velocities.
a) 1:9
b) 3:1
c) 1:27
d) 27:1
29. Which of the following is a stable nucleus?
a) The nucleus with even protons and odd electrons
b) The nucleus with even number of protons and neutrons
c) The nucleus with even neutrons and odd protons
d) The nucleus with odd protons and neutrons
30.Identify the expression for the nuclear radius from the following.
a) R = R0 A1/3
b) R = R0 A1/2
c) R = R0 A3
d) R = R0 A2
31. Which is a non-central force?
a) Electrostatic force
b) Nuclear force
c) Gravitational force
d) Spring force
32. Which of the following is a correct statement?
a) Beta rays are the same as for cathode rays
b) Gamma rays are high energy neutrons
c) Alpha particles are singly ionized helium atoms
d) Protons and neutrons have the same mass
33. The ratio of the nuclear densities of two nuclei having mass numbers 64 and 125 is
a) 64/125
b) 125/64
c) 4/5
d) 1
34. If alpha, beta, and gamma rays carry the same momentum, which has the longest wavelength?
a) Alpha rays
b) Beta rays
c) Gamma rays
d) All have the same wavelength
Explanation- λ=h/p
Directions:
a) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
b) If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
c) If the Assertion is correct but Reason is incorrect.
d) If Assertion is incorrect but Reason is correct.
35. Assertion : Density of all the nuclei is same.
Reason : Radius of nucleus is directly proportional to the cube root of mass number.
A
36. Assertion : Neutrons penetrate matter more readily as compared to protons.
Reason : Neutrons are slightly more massive than protons.
B
37. Assertion : The mass number of a nucleus is always less than its atomic number.
Reason : Mass number of a nucleus is always equal to its atomic number.
D
(d) only In case of hydrogen atom mass number and atomic number are equal.
38. Assertion : The binding energy per nucleon, for nuclei with atomic mass number A > 100, decrease with A.
Reason : The forces are weak for heavier nuclei.
C
(c) Nuclear force is nearly same for all nucleus.
39. Assertion: The free neutron is unstable
Reason: Free neutron disintegrates into proton and antineutrino (
40. Assertion : ZXA undergoes 2α, 2β- particles and 2γ-rays, the daughter product is Z-2YA – 8.
Reason : In α- decay the mass number decreases by 4 and atomic number decreases by 2. In β-decay the mass number remains unchanged, but atomic number increases by 1.
A
41. Assertion : The heavier nuclei tend to have larger N/Z ratio because neutron does not exert electric force.
Reason : Coulomb forces have longer range compared to the nuclear force.
A
42. Assertion : Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion.
Reason : For heavy nuclei, binding energy per nucleon increases with increasing Z while for light nuclei it decreases with increasing Z.
43. 1 u is equal to
a) 9335 Mev b) 931.5 Mev
c) 460 Mev d) 200 Mev
44. Isotones are
a) Same atomic number
b) Same Mass Number
c) Same number of electrons
d) Same number of neutrons
45. Isotopes are
a) Same atomic number
b) Same Mass Number
c) Same number of electrons
d) Same number of neutrons
46. Who had predicted the existence of π-meson in the year 1935
a) Rutherford b) Bohr
c) Dalton d) Yukawa