A capacitor of capacitance 10 μF is connected to a battery of emf 2V. It is found that it takes 50 ms for the charge on the capacitor to become 12.6 μC. Find the resistance of the circuit.
Concepts/Formulas used:
Charging a capacitor:
A capacitor of capacitance C is being charged using a battery of emf ϵ through a resistance R . A switch S is also connected in series with the capacitor. The switch is initially open. The capacitor is uncharged at first. At t=0, the switch is closed
The charge is at any t>0 is given by:
![]()
Note that
is known as time constant.
Given,
Capacitance, ![]()
EMF of battery, ![]()
Resistance, ![]()
We also know that at
, ![]()
We know that,
![]()
![]()
![]()
Taking natural logarithm on both sides, we get
![]()


![]()
![]()
Now,
![]()
![]()
![]()
![]()
![]()