Free Nuclear Physics MCQs with Answers
1,254 Nuclear Physics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Atomic nuclei contain protons and neutrons, with nuclear size, mass defect and binding energy describing their stability. The work covers alpha, beta and gamma decay, decay equations, half-life and decay rate, along with radiation safety and medical applications such as imaging, radiotherapy and tracers.
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- A. N /16
- B. N/8
- C. 15N /16
- D. 7N/8
Explanation: After 4 half-lives, the number of nuclei decayed is 15N /16.
Correct answer: 15N /16- A. Increases by 2, increases by 2
- B. Decreases by 4, decreases by 2
- C. Decreases by 4, increases by 2
- D. Decreases by 4, decreases by 4
Explanation: An alpha particle is represented as ⁴₂He. So, removal of an alpha particle from a parent nuclei would decrease the mass number of the…
Correct answer: Decreases by 4, decreases by 2- A. Temperature
- B. Nature of element
- C. Pressure
- D. Amount of radioactive substance
Explanation: The half-life of a radioactive element is primarily determined by the nature of the element itself.
Correct answer: Nature of element- A. 1820 years
- B. 1620 years
- C. 1940 years
- D. 1680 year
Explanation: This is the correct half-life of Radium-226. Radium-226 has a half-life of approximately 1620 years, which means that after 1620 years…
Correct answer: 1620 years- A. 12
- B. 36
- C. 33
- D. 39
Explanation: Both Xenon and Cesium each have 36 isotopes.
Correct answer: 36- A. 1.66 x 10^-27 g
- B. 1.66 x 10^-24 g
- C. 12 g
- D. 1.66 x 10^-24 kg
Explanation: 1 u = 1 .66 x 10-27 kg = 1.66 x 10-27 (103 g)= 1.66 x 10-24 g
Correct answer: 1.66 x 10^-24 g- A. The number of un-decayed nuclei present at that instant
- B. The time since the decay started
- C. The time remaining before all have decayed
- D. The half-life of the decay
Explanation: A option is accurate. The rate of radioactive decay is directly proportional to the number of undecayed (unstable) nuclei present at a…
Correct answer: The number of un-decayed nuclei present at that instant- A. Photon energies
- B. The kinetic energies of the alpha and the daughter nucleus
- C. The excitation energy of the daughter nucleus
- D. The excitation energy of the alpha particle
Explanation: Option B is the most accurate description. In alpha decay, a heavy, unstable nucleus emits an alpha particle (which is a helium nucleus…
Correct answer: The kinetic energies of the alpha and the daughter nucleus- A. 1:2:3
- B. 3:2:1
- C. 2:1:3
- D. 2:3:1
Explanation: The ratio of activity of radioactive substance remains the same after a particular time interval.So,A1:A2:A3 = 1:2:3
Correct answer: 1:2:3- A. α,β,γ
- B. γ,α,β
- C. β,α,γ
- D. α,γ,β
Explanation: The equations can be written as:AZX → A-4Z-2Y + αA-4Z-2Y → A-4Z-2Y + βA-4Z-2Y → A-4Z-1K + γ
Correct answer: α,γ,β- A. Curved
- B. Zig-Zag
- C. Straight
- D. Straggling
Explanation: α-particle is about 7000 times more massive than an electron, so it is not easy for it to change its direction from its straight path…
Correct answer: Straight- A. 1.67 x 10^8 years
- B. 4.5 x 10^8 years
- C. 3.3 x 10^9 years
- D. 4.5 x 10^9 years
Explanation: Option D is the most accurate option. The half-life of Uranium-238 is approximately 4.5 x 10^9 years.
Correct answer: 4.5 x 10^9 years- A. 1590 x 10^6 years
- B. 1590 x 10^25 years
- C. 1590 x 10^12 year
- D. Never
Explanation: No radioactive element can completely decay. It is due to the reason that in any half-life period only half of the nuclei decay and in…
Correct answer: Never- A. α-rays
- B. γ-rays
- C. β-rays
- D. All have equal penetrating power
Explanation: The penetrating power of radioactive radiations in the increasing order is given below:α<β<γ
Correct answer: γ-rays995. Radioactivity is:
- A. Spontaneous decaying
- B. Self disintegration property
- C. Chemical property
- D. Both A and B
Explanation: Radioactivity is a natural phenomenon where unstable atomic nuclei spontaneously and self-disintegrate, emitting radiation to achieve…
Correct answer: Both A and B- A. N = Noe-λt
- B. N = Noext
- C. N = Noe-xt/2
- D. No = N(lext)
Explanation: The correct relation would be:N = Noe-λt (Law of radioactivity)
Correct answer: N = Noe-λt- A. α-rays
- B. γ-rays
- C. β-rays
- D. All of the above have same speed
Explanation: Gamma rays have the maximum velocity because they travel at the speed of light, which is faster than both alpha and beta particles.
Correct answer: γ-rays- A. Antiproton
- B. Gamma rays
- C. Positron
- D. Photon
Explanation: A particle having the mass of an electron and the charge of a proton is called positron. It is the anti-particle of electron.
Correct answer: Positron- A. Neutrino
- B. α-particle
- C. Anti-neutrino
- D. Positron
Explanation: During o-1 β emission, an anti-neutrino is emitted. While in case of o+1 β emission, a neutrino is emitted.
Correct answer: Anti-neutrino- A. Rectilinear
- B. Zigzag or erratic
- C. Carved
- D. Elliptical
Explanation: β -particles are more easily deflected by collisions than heavy α-particles.
Correct answer: Zigzag or erratic