Question

$20\text{J}$ work has to be done to move a $0.05\text{C}$ point charge from $A$ to $B$ with changing the kinetic energy of point charge by $10\text{J}$. The potential difference $V_B-V_A$ will be,

• A. $400\text{V}$
• B. $-400\text{V}$
• C. $200\text{V}$
• D. $-200\text{V}$

Answer 1

The correct option is C $200\text{V}$

Given, work done $W=20\text{J}$
Point charge, $q=0.05\text{C}$
Change in kinetice energy, $\Delta K.E=10\text{J}$
Potential difference, $\Delta V=V_B-V_A$
So, we have
$W=q\Delta V+\Delta K.E$
or, $20=0.05\Delta V+10$
or, $\Delta V=\frac{10}{0.05}=200\text{V}$
Hence, $\left(C\right)$ is correct answer.