Question

A 10 muF capacitor is charged to a potential difference of 50 V and is connected to another uncharged capacitor in parallel. Now the common potential difference becomes 20 volt. The capacitance of second capacitor is

Answer 1

Answer:

Charge Q=CV . The charge is shared by the two capacitors C1 and C2

Initially, Q=C1*50=500

When capacitors are connected, Q = (C1+C2)*20

or 500=(C1+C2)*20

and so C1+C2= 500/20 or 25 and since C1 is 10 F, then C2 is 25–10 or 15 F