Question

The work done against electric forces in increasing the potential difference of a condenser from 20 V to 40 V is W. The work done in increasing its potential difference from 40 V to 50 V will be

• A. 4W
• B. $\frac{3W}{4}$
• C. 2W
• D. $\frac{W}{2}$

Answer 1

The correct option is D $\frac{W}{2}$

$\begin{array}{c}w=q\Delta v\\ where,\\ q=che\\ \Delta v=potentialdifference\\ w=q\left(40-20\right)\\ w^{{}^{\prime }}=q\left(50-40\right)\\ \frac{w}{w^{{}^{\prime }}}=\frac{20}{10}\\ Hence,\\ w^{{}^{\prime }}=\frac{w}{2}\\ \therefore optionDiscorrectanswer.\end{array}$