Question

A capacitor consists of a set of two parallel plates of area A separated by a distance d. This capacitor carries a charge Q. If the separation between the plates is doubled, the electrical energy stored in the capacitor will be...a) unchangedb) quarteredc) halvedd) doublede) quadrupled

Answer 1

C) Half

Step-by-step explanation:

Given that

Area of plates =A

Distance between plates = d

The charge on the capacitor = C

We know that capacitance C is given as

`C=(\varepsilon _0A)/(d)`

The stored energy U is given as

`U=(1)/(2)CV^2`

When distance gets double ,d ' = 2 d

The value of new capacitance

`C'=(\varepsilon _0A)/(d')`

`C'=(\varepsilon _0A)/(2d)`

`C'=(C)/(2)`

New stored energy U'

`U'=(1)/(2)C'V^2`

`U'=(1)/(2)* (C)/(2)* V^2`

`U'=(1)/(2)* (C)/(2)* V^2`

`U'=(U)/(2)`

Therefore the stored energy get half .

C) Half