The half life of a radioactive substance is … minutes. The approximate time interval … between the time … when … of it had decayed and time … when … of it had decayed is :

Option B. Number of undecayed atom after time …

Atoms and Nuclei

JEE Main 2011 · Annual, Paper 1 · Q6083

PhysicsMedium183×since 2002Q6083

The half life of a radioactive substance is

20

minutes. The approximate time interval

\left( {{t_2} - {t_1}} \right)

between the time

{{t_2}}

when

{2 \over 3}

of it had decayed and time

{{t_1}}

when

{1 \over 3}

of it had decayed is :

JEE Main 2011 · Annual, Paper 1 · Q6083

PhysicsMedium183×since 2002Q6083

The half life of a radioactive substance is

20

minutes. The approximate time interval

\left( {{t_2} - {t_1}} \right)

between the time

{{t_2}}

when

{2 \over 3}

of it had decayed and time

{{t_1}}

when

{1 \over 3}

of it had decayed is :