Question

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, find the value of $V$.

• A. 2 V
• B. 70 V
• C. 5 V
• D. 15 V

Answer 1

Answer: (D)

If we move a charge q from point $A$ to $B$, then potential difference
$ V_B - V_A = \frac{ W_{AB}}{ q} $...(i)
$ V_B = V, \, V_A = 10$ volt,
$W_{ AB} = 20 \,J, q = 4\, C$
On putting these values in Eq. (i)
$V - 10 \frac{ 20}{ 4} $
$V - 10 = 5$
$V= 15$ volt