Question

A regular polygon has 20 sides. Equal

charges, each Q, are placed at 19 vertices of

the polygon and a charge q is placed at the

centre of polygon. If the distance of each

vertex from the centre is ‘a’ , net force

experienced by q is​

Answer 1

Explanation:

In a regular hexagonna each corner is at a distance 'r' from the centre identical charges of magnetude 'Q' are placed at five corners .the field at centre is

centre of polygon. If the distance of each

vertex from

no mention is

Answer 2

Given:

A regular polygon has 20 sides. Equal charges, each Q, are placed at 19 vertices of the polygon and a charge q is placed at the center of polygon.

the distance of each vertex from the center is a.

To Find:

net force experienced by q

Solution:

As we can see from the figure , vertex (1-19) carries the charge Q and the center carries the charge q.

Electric force between the charges of vertex (1-18) and center will be cancelled out by opposite pair of charges in the figure. The only left charge which can generate the electric force will be charge on the vertex 19.

So the electric field generated = KQ/a²

Electric force between Q and q = KQq/a²

Hence the net electric force at the center will be KQq/a².