The half lives of 2 radioactive specimen are $T_1=5$ years. and $T_2=7.5$ years. The ratio of their disintegration constants $λ_1$ and $λ_2$ is:

$\frac{3}{2}$

The correct answer is Option (1) → $\frac{3}{2}$

The relationship between the half life $(T_{1/2})$ and decay constant (λ) is,

$T_{1/2}=\frac{ln2}{λ}$

$∴\frac{λ_1}{λ_1}=\frac{\frac{ln2}{T_1}}{\frac{ln2}{T_2}}=\frac{T_2}{T_1}=\frac{7.5}{5}=\frac{3}{2}$