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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1,254 questions · page 56 of 63
- A. -4
- B. 4
- C. 2
- D. 1
Explanation: When a nucleus emits an alpha particle, these changes happen: the mass number decreases by 4, the atomic number decreases by 2, and the…
Correct answer: 21102. What will happen in a time of 7 hours, if a radioactive substance has an average life of 7 hours?
- A. Half of the active nuclie decay
- B. Less than half of the active nuclie decay
- C. More than half of the active nuclie decay
- D. All active nuclie decay
Explanation: In one average life, i.e. at 7 hours,63.2% of the active nuclie will decay.
Correct answer: More than half of the active nuclie decay- A. U238 contains 3 more protons
- B. U238 contains 3 more protons and 3 more electrons
- C. U238 contains 3 more neutrons and 3 more electrons
- D. U238 contains 3 more neutron
Explanation: Isotopes are the atoms of an element having same atomic number Z but difference mass number A. Thus, U238 contains 3 more neutrons.
Correct answer: U238 contains 3 more neutron- A. A
- B. B
- C. C
- D. D
Explanation: Number of neutrons in Na2311=23-11=12 Number of neutrons in Mg2412=24-12=12
Correct answer: B1105. What is the ratio of the nuclear densities of two nuclie having mass numbers in the ratio 1:4?
- A. 1:1
- B. 1:2
- C. 1:4
- D. 1:3
Explanation: As the nuclear density is independent of mass number, so the ratio of nuclear densities of the two given nuclie is 1:1.
Correct answer: 1:1- A. Spontaneously
- B. When it is heated
- C. When it interacts with the order particles
- D. When it is exposed to light
Explanation: Emission of α β and ϒ-radiation is spontaneous and a random process.
Correct answer: Spontaneously- A. α>β>ϒ
- B. α<β>ϒ
- C. α>β<ϒ
- D. α<β<ϒ
Explanation: The penetrating power of α is least and that of ϒ-radiation is the most.
Correct answer: α<β<ϒ- A. A
- B. B
- C. C
- D. D
Explanation: Number of neutrons in raden=220-86=134 Number of neutrons in polonium=216-84=132
Correct answer: B- A. 172 and 69
- B. 172 and 70
- C. 174 and 70
- D. 176 and 70
Explanation: To summarise, in alpha decay, the atomic number decreases by 2 and the mass number decreases by 4 due to the emission of an alpha…
Correct answer: 172 and 69- A. 1:4
- B. 4:1
- C. 1:8
- D. 8:1
Explanation: Explanation is given below:To find the ratio of their activities after six years, we can use the formula for radioactive decay: Activity =…
Correct answer: 8:1- A. 2T
- B. 4T
- C. 1/2(ln 2)T
- D. 2(ln 2)T
Explanation: When 75% decays, 25%is left un-decayed. The requires a time t=2T1/2, where
Correct answer: 2(ln 2)T- A. A
- B. B
- C. C
- D. D
Explanation: Explanation is given below: As t=T/2 T= half life So, after n half lives N=No(1/2)^n, where n=T/2T=1/2 As we are asked for the fraction of…
Correct answer: B- A. Iodine 131
- B. Carbon 14
- C. Phosphorous 32
- D. Carbon 12
Explanation: For skin cancer phosphorous-32 or strontium-90 may be used. Phosphorus-32 is a radioactive isotope of phosphorus.
Correct answer: Phosphorous 32- A. Fever
- B. Liver
- C. Bones
- D. Cancer
Explanation: This is the correct answer. Cobalt-60 is primarily used in radiation therapy for the treatment of cancer.
Correct answer: Cancer- A. Must be very reactive chemically
- B. Has an atomic number that is one more than that of "X"
- C. Has a mass number that is one less than that of "X"
- D. Must be radioactive
Explanation: This statement is accurate. When a β-particle is emitted, the atomic number of the resulting atom is one greater than that of the original…
Correct answer: Has an atomic number that is one more than that of "X"- A. Remains constant with time
- B. Decrease with time
- C. Increase with time
- D. May increase or decrease with time
Explanation: Rate of decay of radioactive substance decreases exponentially with time.
Correct answer: Decrease with time- A. 9.315 MeV
- B. 931 MeV
- C. 93.45 MeV
- D. 1.025 MeV
Explanation: The following is the solution: 1 u=1.6606 x 10-27 kg =931 MeV
Correct answer: 931 MeV- A. Isotones
- B. Isobars
- C. Isotopes
- D. Isomers
Explanation: The following is the solution: 6C13 and 7N14 have same number of neutrons (N=7). So, they are called isotones.
Correct answer: Isotones- A. 92
- B. 143
- C. 235
- D. Different for different isotopes
Explanation: Atoms of an element having same number of protons but different number of neutron are called isotopes.
Correct answer: Different for different isotopes- A. 1590 x 10^6 years
- B. 1590 x 10^25 years
- C. 1590 x 10^12 year
- D. Never
Explanation: The following is the solution: No radioactive element can completely decay.
Correct answer: Never