Question

In a regular hexgon each corner is at a distance 'r' from the centre. Identical charges of magnitude 'Q' are placed at $5$ corners. The field at the centre is $\left(K=\frac{1}{4\pi {\in }_0}\right)$ ?

• A. $\frac{KQ}{r^2}$
• B. $\frac{6KQ}{r^2}$
• C. $\frac{5KQ}{r^2}$
• D. $Zero$

Answer 1

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

We know,

If identical charges are kept on vertices of a regular hexagon,

Electric Field at origin is zero.

Let us keep a $+Q$ and $-Q$ at the $6^{th}$ vertex,

The $+Q$ charge will sum up zero field with the other 5, $+Q$ charges.

And the left $-Q$ charge will give an electric field of magnitude$=\frac{kQ}{R^2}$

Option $\text{A}$ is the correct answer