Answer:
The current in the circuit when the charge of the capacitor is not changing is 0 A.
Step-by-step explanation:
This question is describing a RC circuit connected to a battery with Emf of E.
The battery charges the capacitor from when the voltage across the capacitor is zero to when it is fully charged at steady state when the charge on the capacitor stops changing.
The current in the circuit at any time can be evaluated in two ways.
The current in the circuit at anytime is the current the flows through the capacitor at that particular time period.
And the current flowing through a capacitor is given as the time derivative of the charge of the capacitor.
I = (dq/dt)
At steady state, when q is not changing with time, (dq/dt) = 0
Hence, the current in the circuit too, at this point is 0 A.
- The second method
The current in the circuit at anytime cam be obtained by dividing the voltage difference between the battery and the capacitor at any time with the Resistance of the resistor.
I = (E - V꜀)/R
Note V꜀ = voltage across the capacitor at any time.
When the charge of the capacitor is not changing, it means the capacitor is fully charged and the voltage across the capacitor has now matched the emf of the battery charging it.
when V꜀ = E
I = (E - V꜀)/R = (E - E)/R = 0 A
Hope this Helps!!!