Question

Two capacitors of capacitances 2µF and 3µF are charged to 100 V and then plates of capacitors are connected by a connecting wire with polarities shown in the following figure. The heat produced is ______.

Options

• 0

• 24 µJ

• 12 µJ

• 24 mJ

Answer 1

Two capacitors of capacitances 2µF and 3µF are charged to 100 V and then plates of capacitors are connected by a connecting wire with polarities shown in the following figure. The heat produced is 24 mJ.

Explanation:

Heat = Energy loss = `1/2 (C_1C_2)/(C_1 + C_2) (V_1 - V_2)^2`

Here, V₁ = 100 V and V₂ = -100 V

(-ve sign signifies that the capacitor is connected in the opposite manner.)

∴ Loss = `1/2 xx ((2 xx 3)/(2 + 3)) xx 10^-6 xx [100 - (-100)]^2`

Loss = 24 × 10^-3 J = 24 mJ