Assertion : The switch `S` shown in the figure is closed at `t = 0`. Initial current flowing through battery is `(E)/(R + r)`
Reason : Initially capacitor was uncharged, so resistance offered by capacitor at `t = 0` is zero

Options

A. If both assertion and reason are ture and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If assertion and reason both are false.

Answer

A

Explanation

(a) Charge on capacitor `q = CE (1 - e^(-t//CR_(eq)))`
`:. I = (dq)/(dt) = (E)/(R_(eq)) e^(-t//CR)`
at `t = 0`
`I = (E)/(R_(eq)) = (E)/(R + r) implies` Resistance offered by capacitor is zero.