How long does it take to fully charge the capacitor in the following case:A capacitor with 4700 μ F is attached to a 12 V power supply and is...

A capacitor with a capacitance C attached in an RC circuit
charges slowly and there is a buildup of a voltage between its plates. It is not
possible to fully charge a capacitor. We can only approach a fully charged state by
passing current through the circuit in which the capacitor is placed over an adequate
duration of time.

After a time equal to 5*RC a steady stead
condition is reached and the capacitor is considered fully
charged.

Here it is given that the voltage across the
capacitor is 12V, it has a capacitance of 4700 micro farad, and a constant current of 15
mA is used to charge it.

The current can be used to
calculate the resistance R = V/I = 12/15*10^-3 = 12000/15 = 800 kilo
ohm.

The time constant of the capacitor is RC = 800 * 10^3
* 4700 * 10^-6

=> 3760
s.

5*RC = 18800 s.

The time
taken to charge the capacitor to approach a steady state condition is 18800
seconds.