Nuclei  MCQs

MCQs of Nuclei

Showing 121 to 130 out of 138 Questions
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121.
The energy released in the explosion of atom bomb is mainly due to _____ .
(a) nuclear fusion
(b) nuclear fission
(c) chemical reaction
(d) radioactive disintegration
Answer:

Option (b)

122.
Critical mass is _____ .
(a) minimum mass for chain reaction
(b) mass necessary for fusion
(c) mass necessary for hydrogen bomb
(d) all of above
Answer:

Option (a)

123.
The law of conservation of _____ is/are obeyed in nuclear reaction.
(a) energy
(b) charge
(c) atomic weight
(d) charge and atomic weight and energy
Answer:

Option (d)

124.
The electron emitted in β-emission is _____ .
(a) emitted from the orbits inside an atom
(b) due to the free electron released in the nucleus
(c) due to disintegration of neutron into the proton
(d) due to the photon escaping from the nucleus.
Answer:

Option (c)

125.
Electron Volt is the unit of _____ physical quantity.
(a) potential difference
(b) electric charge
(c) energy
(d) mass
Answer:

Option (c)

126.
Half life time of plutonium is 24000 years. Its decay is as equation Pu23994 → u23592 + He42. So the part remains undecayed after 73200 years will be _____ .
(a) 0.12
(b) 112
(c) 0.21
(d) 0.81
Answer:

Option (a)

127.
Half life of a element is 20 min. Then time of decay between its 33% and 67% will be _____ min.
(a) 15
(b) 20
(c) 25
(d) 30
Answer:

Option (b)

128.
When Th22890 decays to Bi83212, the number of α and β particle will be _____ respectively.
(a) 4α, 7β
(b) 4α, 1β
(c) 8α, 7β
(d) 4α, 4β
Answer:

Option (b)

129.
The number of nucleus in a radioactive element at a time is 106. If its half life time is 20 sec, then at the end of 10 sec, what is the number of undecayed nucleus in it ?
(a) 1062
(b) 1062
(c) 5 × 105
(d) 2.5 × 105
Answer:

Option (b)

130.
In decay process of U23892 →α XAZ + α then the value of Z and A are _____ .
(a) 92, 236
(b) 88, 232
(c) 90, 234
(d) 91, 234
Answer:

Option (d)

Showing 121 to 130 out of 138 Questions
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