Question

The total charge entering a terminal is given by 1 = (10 – 10e^(-2t))mC. Calculate the current at t = 0.5s

Answer 1

Given:

$q(t)=(10-10e^{-2t})\:\rm mC$

$t_1=0.5\:\rm s$

The electrical current is given by

$$I(t)=\frac{dq(t)}{dt}=20e^{-2t}\:\rm mA$$

At the instant $t=t_1$

$$I(t_1)=20e^{-2*0.5}=7.4\:\rm mA$$