Table of Contents
Introducing the latest Class 12 Physics MCQs for Chapter 13, complete with answers. These MCQs, aligned with the current exam pattern, are designed to enhance students’ understanding of the chapter and help them achieve high scores in their board exams.
Class 12 Nuclei MCQs
Explore multiple-choice questions for the Class 12 Physics chapter on Nuclei. Each question offers four options, with only one correct answer. Students need to select the right option and verify their choice with the provided answers.
Q. The density of nuclei is of the order of:
a) 1010 kg/m3
b) 1014 kg/m3
c) 1017 kg/m3
d) 1021 kg/m3
Answer: b) 1014 kg/m3
Q. A neutron can decay to:
a) Proton and electron
b) Proton, electron, and antineutrino
c) Proton and neutrino
d) Proton, electron, and neutrino
Answer: b) Proton, electron, and antineutrino
Q. The atomic number of an element is determined by:
a) Number of neutrons
b) Number of protons
c) Number of electrons
d) Sum of protons and neutrons
Answer: b) Number of protons
Also Read: Electric Charges and Fields
Q. The half-life of a radioactive substance depends on:
a) Amount of substance
b) Temperature
c) Pressure
d) Nature of substance
Answer: d) Nature of substance
Q. The process of splitting a heavy nucleus into two lighter nuclei is called:
a) Fusion
b) Fission
c) Radioactive decay
d) Beta decay
Answer: b) Fission
Q. In nuclear reactors, the control rods are made of:
a) Cadmium
b) Graphite
c) Plutonium
d) Krypton
Answer: a) Cadmium
Also Read: Current Electricity
Q. The volume of a nucleus is smaller than that of an atom by a factor of:
a) 10
b) 10510^5105
c) 101010^{10}1010
d) 101510^{15}1015
Answer: d) 101510^{15}1015
Q. Which of the following is the best nuclear fuel?
a) Thorium-236
b) Plutonium-239
c) Neptunium-239
d) Uranium-236
Answer: b) Plutonium-239
Q. For the fission of heavy nucleus, neutron is more effective than proton because:
a) Neutron is heavier
b) Neutron is lighter
c) Neutron is uncharged
d) Neutron moves with small velocity
Answer: c) Neutron is uncharged
Read More: Communication System
Q. For thorium with A=232A = 232A=232 and Z=90Z = 90Z=90, at the end of radioactive disintegrations resulting in 82208_{82}^{208}82208Pb, the number of emitted α and β particles are:
a) α = 4, β = 6
b) α = 5, β = 5
c) α = 6, β = 4
d) α = 6, β = 6
Answer: c) α = 6, β = 4
Q. The energy released in the fission of a single 92235_{92}^{235}92235U nucleus is:
a) 200 MeV
b) 300 MeV
c) 400 MeV
d) 500 MeV
Answer: a) 200 MeV
Q. Heavy water is used as a moderator in nuclear reactors to:
a) Absorb neutrons
b) Slow down neutrons
c) Cool the reactor
d) Stop chain reaction
Answer: b) Slow down neutrons
Read More: Wave Optics
Q. The binding energy per nucleon of a nucleus is a measure of its:
a) Stability
b) Instability
c) Radioactivity
d) Mass defect
Answer: a) Stability
Q. The half-life of a radioactive substance is the time taken for:
a) Half of the atoms to decay
b) All atoms to decay
c) The activity to become zero
d) The radiation to stop
Answer: a) Half of the atoms to decay
Q. The process in which a neutron decays into a proton, an electron, and an antineutrino is called:
a) Alpha decay
b) Beta decay
c) Gamma decay
d) Nuclear fusion
Answer: b) Beta decay
Q. Which of the following is a measure of a radioactive material’s instability?
a) Full life
b) Mean life
c) Half-life
d) None of these
Answer: c) Half-life
Q. Radioactive samples are stored in lead boxes because it is:
a) Heavy
b) Strong
c) Good absorber
d) Bad conductor
Answer: c) Good absorber
Q. In nuclear reactions, there is conservation of:
a) Mass only
b) Energy only
c) Momentum only
d) Mass, energy, and momentum
Answer: d) Mass, energy, and momentum
Q. Artificial radioactivity was discovered by:
a) Klaproth
b) Rontgen
c) Irene Curie and Joliot
d) P. Curie and M. Curie
Answer: c) Irene Curie and Joliot
Q. The process of radioactive radiations remains unaffected due to:
a) Physical changes
b) Chemical changes
c) Electric or magnetic fields
d) All of the above
Answer: d) All of the above
Q. An electron emitted in beta radiation originates from:
a) Inner orbits of an atom
b) Free electrons existing in the nucleus
c) Decay of a neutron in the nucleus
d) Photon escaping from the nucleus
Answer: c) Decay of a neutron in the nucleus
Q. The binding energy per nucleon is maximum for nuclei with a mass number around:
a) 50
b) 100
c) 150
d) 200
Answer: b) 100
Q. The primary function ofthe moderator in a nuclear reactor is to:
a) Slow down neutrons
b) Absorb neutrons
c) Cool the reactor
d) Accelerate neutrons
Answer: a) Slow down neutrons
Q. Heavy stable nuclei have more neutrons than protons because:
a) Neutrons are heavier than protons
b) Electrostatic force between protons is repulsive
c) Neutrons decay into protons
d) Nuclear forces between neutrons are weaker than between protons
Answer: b) Electrostatic force between protons is repulsive
Q. The process in which two light nuclei combine to form a heavier nucleus is called:
a) Fission
b) Fusion
c) Radioactive decay
d) Beta decay
Answer: b) Fusion
More Resources for Class 12
- NCERT Solutions Class 12
- NCERT Solutions Class 12 Maths
- NCERT Solutions Class 12 Physics
- NCERT Solutions Class 12 Chemistry
- NCERT Solutions Class 12 Biology
Q. The binding energy of a nucleus is:
a) Energy needed to break the nucleus into its constituent protons and neutrons
b) Energy needed to create the nucleus from its constituent protons and neutrons
c) Energy released during the formation of the nucleus
d) Both a and c
Answer: d) Both a and c
Q. The term ‘radioactive decay’ refers to:
a) Spontaneous disintegration of unstable atomic nuclei
b) Decay of a nucleus by emission of radiation
c) Decay of an atom by losing electrons
d) Both a and b
Answer: d) Both a and b
