Question

Two capacitors of capacitance $4\mu \text{F}\text{and}6\mu \text{F}$are charged to potential of $30\text{V}$ and $20\text{V}$ respectively. If both are connected parallel with positive terminal of the second capacitor and negative terminal with positive terminal of the common potential is

• A. $25\text{V}$
• B. $\text{Zero}$
• C. $15\text{V}$
• D. $24\text{V}$

Answer 1

The correct option is B $\text{Zero}$

As positive terminal of one capacitor is connected to negative terminal of second capacitor, common potential after connection is
$V=\frac{C_1{V}_1-C_2{V}_2}{C_1+C_2}$
$V=\frac{\left[\right(4\times 30)-(6\times 20\left)\right]{10}^{-6}}{(4+6)\times {10}^{-6}}$
$V=0$