Home
Class 12
PHYSICS
What type of energy is stored In capacit...

What type of energy is stored In capacitor?

A

`1/2 Q ^(2) V`

B

`1/2 C ^(2) V`

C

`1/2 (Q ^(2))/(V)`

D

`1/2 QV`

Text Solution

Verified by Experts

The correct Answer is:
D
By energy stored in a charged conductor Suppose, a conductor of capacity C is charged to a potential V and Q the charge on conductor to a potential V and Q acharge conductor at a instatn .
The potential of the conductor
`V = (Q)/(C )`
Now, work done in bringing a small charge dQ at this potential is .
`dW = V dQ = (Q)/(C ) dQ`
`therefore` Total word done in charging it from O to Q is,
`W = int _(0) ^(Q) dW = int _(0) ^(Q) (Q)/(C) dQ `
`= (1)/(2) (Q ^(2))/( C)`
This work stored as the potential energy,
`U = 1/2 (Q ^(2))/( C) " "(because Q = VC)`
`U = (1)/(2) CV ^(2) = (1)/(2) QV`
Promotional Banner

Similar Questions

Explore conceptually related problems

What type of energy is stored in inductor?

The plates of a parallel plate capacitor have an area (20 cm^2) each are separated by a distance of 2.5 mm. The capacitor is charged by connecting it to a 400V supply. How much electrostatic energy is stored in the capacitor?

Draw a graph showing the variation of charge stored in a capacitor with its potential. How will you calculate the energy stored in the capacitor using the above grah?

When we double the separation between two plates by keeping V constant, what happens to total energy stored in the capacitor?

Assertion : When a dielectric slab of dielectric constant K is introduced between the plates after disconnecting the battery, energy stored in the capacitor decreases. Reason : Potential difference between two plates decrease by a factor K ad charge remains the same, so energy decreases.

Derive an expression for energy stored in a capacitor,