Free Nuclear Physics MCQs with Answers

• A. 224, 84
• B. 220, 80
• C. 222, 86
• D. 226, 87

Explanation: Charge no. of daughter nuclei = Z-2 = 88-2 = 86Mass no. of daughter nuclei = A-4 = 226-4 = 222

• A. Trajectory
• B. Firing level
• C. Range
• D. Limit

Explanation: An α-particle travels a well-defined distance in a medium before coming to rest. This distance is called the range of the particle.

• A. (7/8) min
• B. (7/4) min
• C. (8/7) min
• D. (7/2) min

Explanation: After 4T1/2 a sample of radioactive polonium remains = 1/2^4 =1/164T1/2= 14 minT1/2 = 7/2 min

• A. "1" proton and "1" neutron
• B. "3" protons and "3" neutrons
• C. "2" protons and "2" neutrons
• D. "4" protons and "4" neutrons

Explanation: α-particles are helium nuclei. The charge on them is +2e while their mass is 4 amu that is every α-particle has two protons and two…

• A. A option
• B. B option
• C. C option
• D. D option

Explanation: The decay constant of any element is equal to the fraction of decaying atoms per unit time.

• A. Same in all the three
• B. Maximum in α-particles
• C. Maximum in β-particles
• D. Maximum in γ-rays

Explanation: Ionization ability in increasing order is given byγ<β<α

• A. Isobars
• B. Isotones
• C. Isotopes
• D. Isomers

Explanation: Atoms having same atomic mass but different atomic number are called isobars.

• A. can be increased by magnetic field
• B. can be decreased by the magnetic fields
• C. can be kept constant by the electric field
• D. is not effected by electric and magnetic field

Explanation: Radioactivity is a spontaneous, random and natural phenomenon. So, it is not effected by electric and magnetic field

• A. 40%
• B. 50%
• C. 65.6%
• D. 34.4%

Explanation: In 5 years radioactive substance decay = 10 %In 20 years radioactive substance decay = 40 %

• A. Charge of the particle
• B. Mass of the particle
• C. Energy of the particle
• D. All of these

Explanation: An α-particle travels a well define distance in a medium before coming to rest. This distance is called the range of the particle.

• A. 16 hours
• B. 8 hours
• C. 4 hours
• D. 2 hours

Explanation: 15/16 of a radioactive atoms will decay in four half-lives.4T1/2= 16 hoursT1/2= 4 hours

• A. Production of radio waves
• B. Transmissions of radio waves
• C. Reception of radio waves
• D. Decay of atomic nucleus

Explanation: Radioactivity is the phenomenon in which nucleus is disintegrated (decay).

• A. α-particles
• B. β-particles
• C. X-rays
• D. both A and B

Explanation: α and β-particles both radiate energy as X-rays photons when they are slowed by the electric field of the charged particles in the solid…

• A. 72hours
• B. 144 hours
• C. 36 hours
• D. impossible fact

Explanation: After T1/2 the weight of un-decayed radioactive element = 0.5 gAfter 2T1/2 the weight of un-decayed radioactive element = 0.25 g2T1/2=…

• A. Two extra protons and two extra electrons
• B. Two extra protons but no extra electron
• C. Two extra neutrons and no extra electron
• D. Two extra neutrons and two extra electrons

Explanation: For 6C12, p= 6, e = 6, n = 6 For 6C14, p= 6, e = 6, n = 8

• A. 10-14 m
• B. 10-18 m
• C. 10-22 m
• D. 10-26 m

Explanation: By definition, size of nucleus is 10-14 m.

• A. A option
• B. B option
• C. C option
• D. D option

Explanation: By the emission of a β-particle and γ-radiation from the nucleus of neptunium then, "proton number" increases by "1" but "nucleon number"…

• A. 500, 125
• B. 103, 103
• C. 125, 500
• D. 100, 10

Explanation: After 1 sec, 1 half-life will pass so, the remaining activity =103/21 = 500 After 3 sec, 3 half-lives will pass so, Remaining…

• A. Amount of sample present
• B. Pressure
• C. Temperature
• D. None

Explanation: Half-life is a natural process that does not depend upon the amount of sample present, pressure, and temperature.

• A. 3200 years
• B. 4800 years
• C. 2319 years
• D. 4217 years

Explanation: The following is the solution: Behavior of λ with time depends on the nature of the activity.