Nuclei MCQ Questions Class 12 Physics Chapter 13
NCERT MCQ Questions for Class 12 Physics Chapter 13 Nuclei. Nuclei MCQ Questions with Answers from Class 12 Physics.
Nuclei MCQ Questions Class 12 Physics Chapter 13
Nuclei Multiple Choice Questions with Answers Class 12 Physics Chapter 13 PDF is available.
Multiple Choice Questions:
1) The mass of an atom is measured in
a) Kg
b) Mg
c) Atomic mass unit
d) None
Ans: c) atomic mass unit
2) 1amu =
a) 1.66*1027Kg
b) 1.66*10-27 kg
c) 1.660539*10-27kg
d) None
Ans: c) 1.660539*10-27 kg
3) The atomic species of the same element differing in mass are called as
a) Isotopes
b) Isotones
c) Isobars
d) None
Ans: a) isotopes
4) The nucleus of the lightest atom of hydrogen which has a relative abundance of 99.985% is called as
a) Neutron
b) Proton
c) Electron
d) Deuterium
Ans: b) proton
5) The two isotopes of hydrogen are
a) Helium
b) Deuterium
c) Tritium
d) Both b and c
Ans: d) both b and c
6) The atomic number of an atom indicates
a) Number of electrons
b) Number of protons
c) Number neutrons
d) Both number of protons and neutrons
Ans: b) number of protons
7) The atomic mass number of the atom indicates
a) Total number of protons
b) Total number of protons and electrons
c) Total number of protons and neutrons
d) Total number of electrons
Ans: c) total number of protons and neutrons
8) The neutrons and protons are collectively called as
a) Neutrons
b) Mass
c) Nucleons
d) None
Ans: c) nucleons
9) 197Au79, the atomic number is here
a) 79
b) 197
c) 118
d) None
Ans: a) 79
10) 197Au79, the atomic mass number here
a) 197
b) 118
c) 79
d) None
Ans: a) 197
11) 197Au79, the number of protons here
a) 197
b) 79
c) 118
d) None
Ans: b) 79
12) 197Au79, the number of electrons here
a) 197
b) 79
c) 118
d) None
Ans: b) 79
13) 197Au79, the number of nucleons here
a) 197
b) 79
c) 118
d) None
Ans: a) 197
14) 197Au79, the number of neutrons here
a) 197
b) 79
c) 118
d) None
Ans: c) 118
15) Deuterium which is the isotope of hydrogen contains
a) One proton
b) One neutron
c) 2proton
d) Both a and b
Ans: d) both a and b
16) The tritium which is the isotope of hydrogen contains
a) One proton, one neutrons
b) One proton, two neutrons
c) Two protons, one neutrons
d) None
Ans: b) one proton, two neutrons
17) All the nuclides with the same mass number are called as
a) Isotopes
b) Isotones
c) Isobars
d) None
Ans: c) isobars
18) 3H1 and 3He2 are
a) Isotopes
b) Isobars
c) Isotones
d) None
Ans: b) isobars
19) 2H1, 3H1 are
a) Isotones
b) Isobars
c) Isotopes
d) None
Ans: c) isotopes
20) Nuclides with same neutron number but different atomic number are called as
a) Isotopes
b) Isotones
c) Isobars
d) None
Ans: b) isotones
21) 198Hg80 and 197Au79 are called as
a) Isotopes
b) Isotones
c) Isobars
d) None
Ans: b) isotones
22) Total mass of the nucleus is equal to the
a) Total mass of protons in it
b) Total mass of neutrons in it
c) Total mass of its individual protons and neutrons
d) Total mass of protons and electrons
Ans: c) total mass of its individual protons and neutrons
23) The average energy per nucleon needed to separate a nucleus into its individual nucleons is called as
a) Binding energy
b) Binding energy per nucleon
c) Ionisation energy
d) None
Ans: b) binding energy per nucleon
24) The nuclear force is _____ than the coulomb force acting between charges or the gravitational forces between masses.
a) Much weaker
b) Much stronger
c) Both a and b
d) None
Ans: b) much stronger
25) The nuclear force between two nucleons falls rapidly to ____ as their distance is more than a few femtometers.
a) Unity
b) Zero
c) Maximum
d) Minimum
Ans: b) zero
26) The nuclear force between neutron-neutron, proton-neutron and proton – proton is approximately
a) Same
b) Different
c) Both a and b
d) None
Ans: a) same
27) The nuclear phenomenon in which an unstable nucleus undergoes a decay is called as
a) Radioactivity
b) Radioactive decay
c) Nuclear decay
d) None
Ans: b) radioactive decay
28) The decay in which helium nucleus is emitted is called as
a) Beta decay
b) Alpha decay
c) Gamma decay
d) None
Ans: b) aloha decay
29) In alpha decay ____ is emitted
a) Electrons
b) Positrons
c) Helium nucleus
d) High energy photons
Ans: c) helium nucleus
30) The decay in which electrons or positrons are emitted is called as
a) Beta decay
b) Gamma decay
c) Alpha decay
d) None
Ans: a) beta decay
31) In beta decay _____ is emitted.
a) Electrons
b) Positrons
c) Helium nucleus
d) Both a and b
Ans: d) both a and b
32) The decay in which high energy photons are emitted is called as
a) Beta decay
b) Gamma decay
c) Alpha decay
d) Nuclear decay
Ans: b) gamma decay
- In case you have missed:- Previous Chapter MCQ Questions
33) In gamma decay ____ is emitted.
a) Helium nucleus
b) Electrons
c) Positrons
d) High energy photons
Ans: d) high energy photons
34) According to law of radioactive decay, the number of nuclei undergoing the decay per unit time is proportional to the
a) Total number of nuclei in the sample
b) Total number of electrons in the sample
c) Total number of protons in the sample
d) None
Ans: a) total number of nuclei in the sample
35) The number of nuclei undergoing the decay per unit time is proportional to the total number of nuclei in the sample, this is called as
a) Radioactivity
b) Radioactive decay
c) Law of radioactive decay
d) None
Ans: c) law of radioactive decay
36) 1 curie=
a) 3.7*10-10Bq
b) 3.7*1010Bq
c) 3.7*10-7 Bq
d) None
Ans: b) 3.7*1010Bq
37) 238U92234Th 90 + 4He2, shows
a) Beta decay
b) Alpha decay
c) Gamma decay
d) None
Ans: b) alpha decay
38) 32P15 –> 32S16 + e- + v^, shows
a) Alpha decay
b) Beta decay
c) Gamma decay
d) None
Ans: b) beta decay
39) In negative beta decay, the atomic number Z of the nucleus
a) Goes down by 1
b) Goes down by 2
c) Goes up by 1
d) Goes up by 2
Ans: c) goes up by 1
40) In positive beta decay, the atomic number Z of the nucleus
a) Goes up by 1
b) Goes up by 2
c) Goes down by 1
d) Goes down by 2
Ans: c) goes down by 1
41) Here, n p + e- + v^ shows
a) Positive beta decay
b) Negative beta decay
c) Alpha decay
d) Beta decay
Ans: b) negative beta decay
42) Here, p –> n + e+ + v shows
a) Negative beta decay
b) Beta decay
c) Positive beta decay
d) Gamma decay
Ans: c) positive beta decay
43) The process in which a heavy nucleus get fragmented into its lighter nuclei by releasing large amount of energy is called as
a) Nuclear fission
b) Nuclear fusion
c) Both a and b
d) None
Ans: a) nuclear fission
44) The enormous energy released in an atom bomb comes from
a) Nuclear fusion
b) Nuclear fission
c) Uncontrolled nuclear fission
d) None
Ans: c) uncontrolled nuclear fission
45) The measure of the growth rate of the neutrons in the reactor is called as
a) Addition factor
b) Subtraction factor
c) Multiplication factor
d) Division factor
Ans: c) multiplication factor
46) The ratio of number of fission produced by a given generation of neutrons to the number of fission preceding generation is called as
a) Addition factor
b) Division factor
c) Subtraction factor
d) Multiplication factor
Ans: d) multiplication factor
47) For multiplication factor K= 1, the operation of the reactor is said to be
a) Non critical
b) Critical
c) More critical
d) None
Ans: b) critical
48) When fusion is achieved by raising the temperature of the system so that particles have enough kinetic energy to overcome the column repulsive behaviour then it is called as
a) Thermonuclear fission
b) Thermonuclear fusion
c) Nuclear fusion
d) None
Ans: b) thermonuclear fusion
49) The heat energy produced in the sun is due to
a) Nuclear fission
b) Nuclear fusion
c) Both a and b
d) None
Ans: b) nuclear fusion
50) The radius of the nucleus is ____ than the radius of the atom by a factor of 104.
a) Larger
b) Smaller
c) Both a and b
d) None
Ans: b) smaller
51) More than 99.9% mass of the atom is concentrated in the
a) Centre
b) Orbit
c) Electrons
d) Nucleus
Ans: d) nucleus
52) A nucleus contains the neutral particle which is called as
a) Proton
b) Electron
c) Neutron
d) Helium
Ans: c) neutron
53) The difference in the mass of a nucleus and it’s constituents is called as
a) Mass difference
b) Mass defect
c) Mass ration
d) None
Ans: b) mass defect
54) Energies associated with nuclear processes are about a million times ____ than chemical processes.
a) Smaller
b) Larger
c) Medium
d) None
Ans: b) larger
55) The disintegration or decay constant has unit
a) Second
b) 1/second
c) Js
d) None
Ans: b) 1/second
56) The half life and mean life is measured in
a) Day
b) Year
c) Month
d) Second
Ans: d) second
57) Activity of radioactive sample is measured in
a) J
b) N
c) Bq
d) None
Ans: c) Bq
58) Fusion requires ____ temperature.
a) Low
b) Very low
c) High
d) Very high
Ans: d) very high
59) The light nuclei have sufficient initial energy to overcome the coulomb potential barrier in case of
a) Nuclear fission
b) Nuclear fusion
c) Radioactive decay
d) None
Ans: b) nuclear fusion
60) Electrons and positrons are
a) Antiparticle – particle pair
b) Antiparticle pair
c) Particle – antiparticle pair
d) None
Ans: c) particle – antiparticle pair
61) A free neutron is
a) Stable
b) Unstable
c) Both a and b
d) None
Ans: b) unstable
62) A proton is ____ than a neutron.
a) Heavier
b) Lighter
c) Both a and b
d) None
Ans: b) lighter
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