A parallel-plate capacitor having plate area 25 cm2 and separation 1.00 mm is connected to a battery of 6.0V. Calculate the charge flown through the battery. How much work has been done by the battery during the process?
Given
Area, A=25 cm2 =25×10-4 m2
Voltage, V=6V
The separation between the plates is d= 1mm=1×10-3
Formula used:
When a capacitor is connected to a capacitor, the charge can be calculated
Where
Q is the charge of the capacitor
C is the capacitance of the capacitor
V is the Voltage or potential difference across the plates of the capacitor.
Capacitance C can be calculated by the formula
Where
C is the capacitance of the capacitor
D is the separation between the capacitor plates
A is the area of a circular plate capacitor
ε₀ is the permittivity of the free space, 
When the capacitor is connected to a 6V battery, Charge flow through the battery is the same as the charge that can be withstand with the capacitor.
Substitute the value of C in 1)
Work is done by the battery
Where
W is the work done by the battery
Q is the charge on the plates of the capacitor
V is the voltage across the plates of the capacitor
Charge flows through the battery is 
and work done by the battery is =8×10-10 J