# If $20\;J$ of work has to be done to move an electric charge of $4\; C$ from a point, where potential is $10\; V$ to another point, where potential is V volt, then find the value of V.

Here, $W_{AB} = 20\; J, \qquad q_0 = 4C, \qquad V_A = 10 V \qquad V_B = V = ?$
We know $V_B -V_B =\large\frac{W_{AB}}{q_0}$
$V-10 =\large\frac{20}{4}$$=5$
$V= 5+ 10=15V$