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

Answer: (B)

$1500\sqrt{2}volt$

Answer 2

Potential at the centre O,

$V = 4 \times \frac{1}{4\pi\varepsilon_{0}}.\frac{Q}{a/\sqrt{2}}$

where $Q = \frac{10}{3} \times 10^{- 9}C$ and $a = 8cm = 8 \times 10^{- 2}m$

So $V = 5 \times 9 \times 10^{9} \times \frac{\frac{10}{3} \times 10^{- 9}}{\frac{8 \times 10^{- 2}}{\sqrt{2}}} = 1500\sqrt{2}volt$