Question

If the potential of a capacitor of capacity 6 μF is increased from 10 V to 20 V, the increase in its energy will be:

• A. 4 × 10⁻⁴ J
• B. 4 × 10⁻⁶ J
• C. 9 × 10⁻⁴ J
• D. 12 × 10⁻⁶ J

Hint:

Capacitor energy depends on square of voltage.

Answer 1

The Correct Option is C

Step 1: Energy formula of capacitor. U = (1)/(2)CV²
Step 2: Calculating energies. Initial energy: U₁ = (1)/(2) × 6×10⁻⁶ × 10² Final energy: U₂ = (1)/(2) × 6×10⁻⁶ × 20²
Step 3: Increase in energy. Δ U = U₂ - U₁ = 9 × 10⁻⁴ J