SECTION - B (a) Define one Becquerel. (b) A radioactive substance disintegrates into two types of daughter nuclei, one type with disintegration constant \lambda_1 and the other type with disintegration constant \lambda_2. Determine the half-line of the radioactive substance.

CBSE Class 12 Physics 2020 Delhi Set 2 Paper - Question 4

Question : 4 of 7

Marks: +1, -0

SECTION - B

(a) Define one Becquerel.
(b) A radioactive substance disintegrates into two types of daughter nuclei, one type with disintegration constant

λ_1

and the other type with disintegration constant

λ_2

. Determine the half-line of the radioactive substance.

Solution:

(a) Becquerel: One Becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second.
(b)

λ=λ_1+λ_2

Or,

\;{0.693}/{T_{1 \/ 2}}=λ_1+λ_2

∴ \;\; T_{1 \/ 2}=\;{0.693}/{λ_1+λ_2}

Go to Question:

Prev Question

Next Question