Question

A capacitor of capacity c has charge q and stored energy is w. if the charge is increased to 2q then what will be stored energy

Answer 1

it is the energy of charge 2q.

Answer 2

Answer:

The stored energy will increase 4 times on increasing charge to 2 q.

Explanation:

It is given that, a capacitor of capacity c has charge q and stored energy is w. We have to find the new energy stored in the capacitor when the charge is 2 q.

The energy stored in a capacitor is given by :

$U=\dfrac{q^2}{2C}$.....(1)

Where

q is the charge

C is the capacitance of the capacitor

It is clear form equation (1) that energy stored in capacitor is directly proportional to the charge.

According to question, $w=\dfrac{q^2}{2c}$..

On increasing charge to 2 q, let new energy is w'. So,

$w'=\dfrac{(2q)^2}{2c}$

$w'=4\dfrac{(q)^2}{2c}$

w' = 4 w

Hence, the stored energy will increase 4 times on increasing charge to 2 q.