Two capacitors of 100 ~F and 50 ~F are connected in parallel. If the potential difference across 100 ~F is 20 V and across 50 ~F is 40 V , then the common potential of the parallel combination will be (same polarities of the capacitor connected together)

Step-by-step solution

Parallel Combination Common Potential The initial charges are Q₁ = C₁ V₁ = (100 10⁻⁶) 20 = 2 10⁻³ C and Q₂ = C₂ V₂ = (50 10⁻⁶) 40 = 2 10⁻³ C. Using conservation of charge, the total charge becomes Q_ total = Q₁ + Q₂ = 4 10⁻³ C. The equivalent capacitance is C_ eq = C₁ + C₂ = 150 10⁻⁶ F. The common potential is calculated using V_ common = Q_ total C_ eq . V_ common = 4 10⁻³ 150 10⁻⁶ = 80 3 V. The common potential is 80 3 V.