Two identical capacitors A and B are charged to the same potential V and are connected in two circuits at t = 0 as shown in figure. The charge of the capacitors at a time t = CR are respectively -

Options

A. VC,
B. `(VC)/(e ),VC`
C. `VC, (VC)/(e)`
D. `(VC)/(e),(VC)/(e)`

Answer

B

Explanation

(i) Time constant `(tau)=RC`
Time constant is the time in which charge on capacitor decreases to `(1)/(e )` times of its initial charge (steady state charge )
As D is in `FB implies "At t"=RC, Q=(CV)/(e)`
(ii) Diode is in RB. So no current will flow through the circuit hence charge on capacitor will not decay and it remains same, i.e. Q=CV .