The activity of a radioactive sample is \[{{A}_{1}}\] at time \[{{t}_{1}}\] and \[{{A}_{2}}\] at time\[{{t}_{2}}\]. If \[\tau \] is average life of sample then the number of nuclei decayed in time (\[{{t}_{2}}-{{t}_{1}}\]) is

\[{{A}_{1}}{{t}_{1}}-{{A}_{2}}{{t}_{2}}\]

\[\frac{\left( {{A}_{2}}-{{A}_{1}} \right)}{2}\tau \]

\[\left( {{A}_{1}}-{{A}_{2}} \right)\left( {{t}_{2}}-{{t}_{1}} \right)\]

\[\left( {{A}_{1}}-{{A}_{2}} \right)\tau .\]

The activity of a radioactive sample is \[{{A}_{1}}\] at time \[{{t}_{

1.	The activity of a radioactive sample is \[{{A}_{1}}\] at time \[{{t}_{1}}\] and \[{{A}_{2}}\] at time\[{{t}_{2}}\]. If \[\tau \] is average life of sample then the number of nuclei decayed in time (\[{{t}_{2}}-{{t}_{1}}\]) is
A.	\[{{A}_{1}}{{t}_{1}}-{{A}_{2}}{{t}_{2}}\]
B.	\[\frac{\left( {{A}_{2}}-{{A}_{1}} \right)}{2}\tau \]
C.	\[\left( {{A}_{1}}-{{A}_{2}} \right)\left( {{t}_{2}}-{{t}_{1}} \right)\]
D.	\[\left( {{A}_{1}}-{{A}_{2}} \right)\tau .\]
Answer» E.