In Question 6, the capacitor will reach full charge in a time equal to approximately

ANS:B - 5 RC

V (Capacitor) = V(1-e^[-t/T]).

Put [t=T].

V(c) = V(1-e^[-1]).

As we know e^[-1] = 0.37 above answer will be 0.63.

Similarly put [t = 5T].

V(c) = V(1-e^[-5T/T]).

V(c) = V(1-e^[-5]).

V(c) = V(0. 9932) which is nearly equal to 100% it means at 5T we are getting the capacitor fully charged.