Two point charges +8q and -2q are located at x = 0 and x = L respectively . The location of a point on a x - axis at which the net electric field due to these two point charges is zero from charge 8q is :

Options

A. 2L
B. `L/4`
C. `8L`
D. `4L`

Answer

A

Explanation

For zero electric field , the electric field of both charges at that point should be equal and opposite , so
`(K(2q))/(d^(2)) = (K(8q))/((L+d)^(2))`
`rArr L + d = 2d " " rArr d = L `
Distance form origin ` = (L+L) = 2L `