Two protons are kept at a separation of 40 . Fn is the nuclear force and Fe is the electrostatic force between them. Then
Fn >> Fe
Fn = Fe
Fn << Fe
Fn ≈ Fe
The ratio of the nuclear radii of elements with mass numbers 216 and 125 is
216 : 125
6 : 5
None of these
On bombarding U235 by slow neutron, 200 MeV energy is released. If the power output of atomic reactor is 1.6 MW, then the rate of fission will be
5 × 1022/s
5 × 1016/s
8 × 1016/s
20 ×1016/s
The masses of two radioactive substances are same and their half-lives are 1 yr and 2 yr respectively. The ratio of their activities after 4 yr will be
1 : 4
1 : 2
1 : 3
1 : 6
92U235 undergoes successive disintegrations with the end product of 82Pb203. The number of α and β particles emitted are
α = 6, β = 4
α = 6, β = 0
α = 8, β = 6
α = 3, β = 3
In a radioactive disintegration, the ratio of initial number of atoms to the number of atoms present at an instant of time equal to its mean life is
e
e2
C.
e
Let the initial number of atoms at time t = 0 be N0.
Let N be the number of atoms at any instant t.
Mean life , where λ is disintegration constant.
Given, t = ζ
According to radioactive disintegration law,
β- decay means emission of electron from
innermost electron orbit
a stable nucleus
outermost electron orbit
radioactive nucleus