List of top Physics Questions on Half life asked in KCET

The half-life of tritium is 12.5 years. What mass of tritium of initial mass 64 mg will remain undecayed after 50 years ?

The half life of a radioactive substance is $20\, minutes$. The time taken between $50\%$ decay and $87.5\%$ decay of the substance will be

The relation between half life $(T)$ and decay constant $(\lambda)$ is