A condcuting slab of thickness `d/2` is inserted between the plates of parallel plate capacitor as shown in the figure . The energy stored in the capacitor when terminals of capacitor are connected across a battery of emf 2V is (plate area is A)

Options

A. `(2Aepsi_0)/(d)V^2`
B. `(Aepsi_0)/(2d)V^2`
C. `(Aepsi_0)/(d) V^2`
D. `(4Aepsi_0)/(d) V^2`

Answer

D

Explanation

`C=(epsi_0A)/(d-t(1-1/K))`

`U=1/2C_(AB) V_(AB)^2`
`C_(AB) = (epsi_0A)/(d-1/2 (1-1/oo))`
`=(2Aepsi_0)/(d)`
`U=1/2CV^2`
`=1/2 (2Aepsi_0)/(d) (2V)^2`
`=(4Aepsi_0V^2)/(d)`