Energy released in the fission of a single 92U235 nucleus is 200 MeV. The fission rate of a 92U235 filled reactor operating at a power level of 5 W is
1. 56 × 10-10 s -1
1. 56 × 1011 s-1
1. 56 × 10-16 s-1
1. 56 × 10 -17 s-1
Alpha particles are
2 free protons
helium atoms
singly ionized helium atoms
doubly ionized helium atoms
In a given reaction:
Radioactive radiations are emitted in the sequence of
α, β, γ
γ, β, α
γ, α, β
β, α, γ
The nuclei 6C13 and 7N14 can be described as
isotones
isobars
isotopes of carbon
isotopes of nitrogen
The ratio of the radii of the nuclei 13Al27 and 52Te125 is approximately
6 :10
13 : 52
40 : 177
14 : 73
Solar energy is due to
fusion reaction
fission reaction
combustion reaction
chemical reaction
The mass density of a nucleus varies with mass number A as
A2
A
constant
1/A
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
4 microcurie
8 microcurie
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
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.