Question

Starting with a capacitor charged to 30V, how long will it take to completely discharge it?

a.) 30 sec

b.) 10 sec

c.) The capacitor would technically never discharge completely

d.) Not enough information is given to answer this question

Answer 1

Since the capacitor discharge equation is given by

V_t = V_o (e^-t/RC)

For fully discharging the capacitor,

Vt = 0

=> 0 = V_o (e^-t/RC)

Vo = 30V

=>e^-t/RC = 0

This is only possible when,

t/RC -> $\infty$

=> RC -> 0

Therefore we can say that the capacitor would never technically fully discharge

Hence,

Correct option is C