Question

In a regular polygon of $n$ sides, each corner is at a distance $r$ from the centre. Identical charges of magnitude $q$ are placed at $(n-1)$ corners. The field at the centre is

• A. $k\frac{q}{r^2}$
• B. $(n-1)k\frac{q}{r^2}$
• C. $\frac{n}{n-1}k\frac{q}{r^2}$
• D. $\frac{n-1}{n}k\frac{q}{r^2}$

Answer 1

The correct option is A $k\frac{q}{r^2}$

If charges were kept at all corners resultant electric field would

have been zero. so, removal of one charge would result in the same electric field as due to one charge alone.

So, $E=\frac{KQ}{r^2}$.

Option $A$ is correct.