Question

two charges 9e and 3e are placed at distance r. the distance of the point where the electric field iintensity will be zero is ?

Answer 1

But I'm not sure about answer....

Answer 2

Dear friends,

Let distance at which electric field intesity is zero be 'a' from 9e charge.

so putting formula, the electric field for 3e and 9e will be equal,

1/(4*pi*epsilon0) *(9e/a^2) = 1/(4*pi*epsilon0) *(3e/(r-a)^2)

=>3(r-a)^2 = a^2

solving we get,

a= r*sqrt(3)/(sqrt(3)+1)= r*(3-sqrt(3))/2 [Ans]

Regards,

Thank you,

RUSHANG PATEL