Question

Charges of $+\frac{10}{3}\times {10}^{-9}C$ are placed at each of the four corners of a square of side $8cm$. The potential at the intersection of the diagonals is

• A. $150\sqrt{2}volt$
• B. $1500\sqrt{2}volt$
• C. $900\sqrt{2}volt$
• D. $900volt$

Answer 1

The correct option is B $1500\sqrt{2}volt$

Charges of $=+\frac{10}{3}\times {10}^{-9}C$

side $a=8cm$

Potential at the centre $0$

$V=\frac{4Q}{4\pi {ϵ}_0{\left(a/2\right)}^{1/2}}$

where,

$Q=\frac{10}{3}\times {10}^{-9}C$

and $a=8cm=8\times {10}^{-2}m$

So,

$V=4\times 9\times 109\times 103\times {10}^{-9}\times 8\times {10}^{-2}$

$=1500\times 2^{1/2}V$

$=1500\sqrt{2}V$