Which of the following statements is true for nuclear forces?
They obey the inverse square law of distance.
They obey the inverse third power law of distance.
They are short range forces.
They are equal in strength to electromagnetic forces.
The average binding energy of a nucleon inside an atomic nucleus is about
8 MeV
8 eV
8 J
8 erg
The ratio of the radii of the nuclei 13Al27 and 52Te125 is approximately
6 :10
13 : 52
40 : 177
14 : 73
Heavy water is used as a moderator in a nuclear reactor. The function of the moderator is
To control energy released in the reactor
To absorb neutrons and stop chain reaction
To cool the reactor
To slow down the neutrons to thermal energies
The nucleus 48Cd115, after two successive β-decay will give
46Pa115
49In114
<p><sub>50</sub>Sn<sup>113</sup></p>
<p><sub>50</sub>Sn<sup>115</sup></p>
In a given reaction:
Radioactive radiations are emitted in the sequence of
α, β, γ
γ, β, α
γ, α, β
β, α, γ
A radioactive sample with a half-life of 1 month has the label: ‘Activity = 2 microcurie on 1 – 8 – 1991’. What would be its activity two months earlier?
1.0 microcurie
0.5 microcurie
8 microcurie
The half-life of radium is 1600 yr. The fraction of a sample of radium that would remain after 6400 yr is
1/4
1/2
1/8
1/16
The binding energy per nucleon is maximum in case of
2He4
26Fe56
56Ba141
92U235
A radioactive element has half-life period 800 yr. After 6400 yr what amount will remain?
1/256
