S32 absorbs energy and decays into which element after two -emissions?
Carbon
Aluminium
Oxygen
magnesium
Among the following which is used to control the rate of reaction of nuclear fissions reactions?
Water
Heavy water
Cadmium
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Assertion: For nuclear reactor, it is desirable to have k = 1.
Reason: Sustained chain reaction occur at this critical condition.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Mass defect in nuclear reactions is less than 1%.
Reason: In nuclear reaction change in BE/N is generally less than 1%.
If both assertion and reason are true and reason is correct explanation of asertion.
If both assertion and reason are true and reason is not correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: It is very easy to detect neutrino in nature.
Reason: It has high affinity to interact with matter.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both asertion and reason are true and reason is not correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: It is desirable to slow down fast moving neutrons to sustain controlled chain reactions.
Reason: Slow moving neutrons efficiently collides with U235.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If assertion and reason are false.
Two radioactive substances A and 8 have decay constants 5A and A respectively. At I =0, they have the same number of nuclei. The ratio of number of nuclei of A to those of 8 will be (1/e2 ) after a time
4λ
2λ
C.
At t = 0, N =N0 for both the substances A and B
N = N0 and NB = N0
=
=
= e( λ - 5 λ) t
= e-4λt
=
Since according to question the ratio of nuclei of thos A to thoas B will be (1/e2)
∴ 4λt = 2
t =
t =
The intensity of gamma radiation from a given source is I. On passing through 36 mm of lead, it is reduced to l/8. The thickness of lead which will reduce the intensity to l/2 will be
18 mm
12 mm
6 mm
9 mm
A nucleus of mass number 220 decays by decay. The energy released in the reaction is 5 MeV. The kinetic energy of an -particle is
MeV
MeV
MeV
MeV