A charged capacitor of capacity `C` is discharge through a resistance `R`. A radioactive sample decays with an average life `J`. If the ratio of electrostatic field energy stored in the capacitor to the activity of the radioactive sample remains constant with time then `R=(xJ//C)`. where `x` is ________

Answer

B

Explanation

`(E)/(A)((1)/(2C)(Q_(0)e^(-t//RC))^(2))/(A_(0)e^(-lambda t))` For this ratio to be constant,
with time , `(2 t)/(RC)= lambda t` or `lambda =(2)/(CR) ,(1)/(J)=(2)/(CR)`