Question

The energy required to charge a parallel plate condenser of plate separtion `d` and plate area of cross-section `A` such that the unifom field between the plates is `E` is
A. `(1)/(2)epsilon_(0)E^(2)//Ad`
B. `epsilon_(0)E^(2)//Ad`
C. `epsilon_(0)E^(2)Ad`
D. `(1)/(2)epsilon_(0)E^(2)Ad`

Answer 1

Correct Answer - C
Energy given by the cell, `E=CV^(2)`
Here, C = capacitiance of condenser `=(Aepsilon_(0))/(d)`
V = potential across the plates = Ed
Therefore, `E=((Aepsilon_(0))/(d))(Ed)^(2)=Aepsilon_(0)E^(2)d`