A radioactive nucleus A with a half life

PHYSICS · Single correct · CBSE · Physics · Nuclei · Nuclei

Problem

T

, decays into a nucleus B. At

t=0

, there is no nucleus B. At sometime

t

, the ratio of the number of B to that of A is 0.3. Then,

t

is given by [Main 2017] (1)

t = T \log (1.3)

(2)

t = \frac{T}{\log(1.3)}

(3)

t = T \frac{\log 2}{\log 1.3}

(4)

t = \frac{\log 1.3}{\log 2}