Question

A capacitor of capacitance 2 µF is charged to a potential of 100 V and another capacitance 6 µF is charged to a potential of 300 V. These capacitors are joined, with plates of like charges connected together, the total charge is ____________.

Options

• 16 x 10^-4 C

• 18 x 10^-4 C

• 20 x 10^-4 C

• 24 x 10^-4 C

Answer 1

A capacitor of capacitance 2 µF is charged to a potential of 100 V and another capacitance 6 µF is charged to a potential of 300 V. These capacitors are joined, with plates of like charges connected together, the total charge is 20 x 10^-4 C.

Explanation:

Total charge Q = Q₁ + Q₂

= C₁V₁ + C₂V₂

= 2 x 10^-6 x 100 + 6 x 10^-6 x 300

= 200 x 10^-6 + 1800 x 10^-6

= 2000 x 10^-6 C

= 20 x 10^-4 C.