Question

A capacitor of $20 \mu F$ is charged upto 500V is connected in parallel with another capacitor of $10 \mu F$ which is charged upto 200V. The common potential is

• A. 500V
• B. 400V
• C. 300V
• D. 200V

Answer 1

Answer: (B)

400V

Answer 2

By using $V = \frac { C _ { 1 } V _ { 1 } + C _ { 2 } V _ { 2 } } { C _ { 1 } V _ { 2 } }$; C₁ = 20 μF, V₁ = 500 V, C₂ = 10 μF and V₂ = 200 V

$V = \frac { 20 \times 500 + 10 \times 200 } { 20 + 10 } = 400 \mathrm {~V}$