Question

Electric charges $+10\mu C,+5\mu C,and+8\mu C$ are placed at the corners of a square of side $\sqrt{2}m$. The potential at the centre of the square is

• A. $18\times {10}^{5}V$
• B. $1.8\times {10}^{6}V$
• C. 1.8 V
• D. $1.8\times {10}^{5}V$

Answer 1

The correct option is D

$1.8\times {10}^{5}V$

Distance of corner from centre

$=\frac{1}{2}\sqrt{(\sqrt{2}{)}^2+(\sqrt{2}{)}^{2}m}=1mV=\frac{9\times {10}^9}{1}[10+5-3+8]\times {10}^{-6}\text{volt}=1.8\times {10}^5\text{volt}$