Question

47 μF capacitor is charged to 6.0 V and then discharged through a 1.0 MΩ resistor.

Calculate the inital current and time constant

Answer 1

(a) We can find the initial current from the Ohm's law:

$$I=\dfrac{V}{R}=\dfrac{6.0\ V}{1.0\cdot10^6\ \Omega}=6\cdot10^{-6}\ A.$$

(b) The time constant can be found as follows:

$$\tau=RC=1.0\cdot10^6\ \Omega\cdot47\cdot10^{-6}\ F=47\ s.$$