Question

A $5\mu F$ capacitor is charged to 12 V. The positive plate of the capacitor is connected to the negative terminal of a 12 V battery and vice versa. Find the heat developed in the connecting wires :

• A. $72\mu J$
• B. $720\mu J$
• C. $1.44\mu J$
• D. $144\mu J$

Answer 1

The correct option is C $1.44\mu J$

The capacitor is connected to the battery so its potential remains constant. As they are connected in opposite polarity so potential across capacitor is $V=12+12=24V$
Here the stored energy in capacitor will develop heat in the connecting wires.
Thus, the heat, $H=U=\frac{1}{2}C{V}^2=0.5\times 5\times {10}^{-6}\times {24}^2=1.44\mu J$