Question

A 20.0 F capacitor initially charged to 30.0 uC is discharged through a 3.00 k resistor. How long does it take to reduce the capacitor's charge to 15.0 C? Express your answer with the appropriate units. ?

Answer 1

Answer:

t = 0.04159 s

Explanation:

when a capacitor and resister are connected in series. charge on its plates decreases exponentially

$q = qo * e^{\frac{-t}{RC}}$

where,

CHARGE q  =15.0 C

INITIAL CHARGE q_0 = 30.0 uc

Resistor R = 20.0 F

capacitor C  = 3.00

$15 = 30* e^{\frac{- t}{(20* 10^{-6} * 3* 1000)}$

t = 0.04159 s