Question

A parallel plate capacitor of capacitance c is charged to a potential v it is then connected to another uncharged capacitor having the same capacitance find the ratio of energy stored in the combined system to that stored initally in the single capacitor

Answer 1

Hey mate!!

Initially energy stored in capacitor is

U= Q²/2C

Now, when another uncharged capacitor is added in circuit.

Find V common

V common= (q1+q2) / (C1+C2)

Where q2= 0

So,

V common= q/2C

·.· energy on each capacitor

= 1/2CV²common

U= 1/2C(q²/2C)

Now taking their ratio initial:final

U1/U2= (q²/2C) / (q²/8C)

U1/U2= 4:1

Hope it helps!

#phoenix