In an LCR circuit as shown below both switches are open initially. Now switch `S_(1)` kept open. (q is charge on the capacitor and `tau = RC` is Capacitive time constant). Which of the following statement is correct?

Options

A. At `t=(tau), q=CV//6`
B. At `t=(tau), q=CV//2`
C. At `t=2(tau), q=CV(1-e^(-2))`
D. At `t=2(tau), q=CV(1-e^(-1))`

Answer

C

Explanation

(c) Charge on he capacitor at any time t is given by
`q=CV(1-e^(t//tau))`
at `t=2 tau`
`q=CV(1-e^(-2))`.