Two identical capacitors, have the same capacitance C. One of them is charged to potential `V_1` and the other `V_2`. The negative ends of the capacitors are connected together. When the poistive ends are also connected, the decrease in energy of the combined system is

Options

A. `1/4C(V_(1)^(2)-V_(2)^(2))`
B. `1/4C(V_(1)^(2)+V_(2)^(2))`
C. `1/4C(V_(1)-V_(2))^(2)`
D. `1/4C(V_(1)+V_(2))^(2)`

Answer

C

Explanation

`DeltaU=` 'd'`ecrease in potential 'energy, `U_i-U f,=1/2C(V_1^(2)+V_2^(2))-1/2(2C)((V_1+V_2)/2)^(2)=1/4C(V_1-V_2)^(2)`