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
A. `10 muF`
B. `20 muF`
C. `30 muF`
D. `15 muF`

Answer 1

Correct Answer - D
`V = (C_(1)V_(1) + C_(2)V_(2))/(C_(1) + C_(2)) rArr 20 = (10 xx 50 + C_(2) xx 0)/(10 + C_(2))`
`rArr 200 + 20C_(2) = 500 rArr C_(2) = 15 muF`