Question

A charge q produces an electric field of strength 4E at a distance of d away. Determine the electric field strength at a distance of 1/3d away.

Answer 1

distance is 1/3 of the original, force is 9x the original force.

Answer 2

Electric field strength is 4E/9

Step-by-step explanation:

It is given that, a charge q produces an electric field of strength 4E at a distance of d away.

The electric field at a distance d is given by :

`E=k(q)/(d^2)`......(1)

According to question,
`4E=k(q)/(d^2)`........(2)

From equation (1), it is clear that electric field strength is inversely proportional to the square of distance between them.

We have to find the electric field strength (E') at a distance of 1/3d away. So,

`E'=k(q)/((d/3)^2)`............(3)

Taking ratios of equation (2) and (3). So,

`(4E)/(E')=(k(q)/(d^2))/(k(q)/((d/3)^2))`

`(4E)/(E')=9`

`E'=(4E)/(9)`

So, the electric field strength at a distance of (1/3)d away is 4E/9