Question

Charge q₁=1.00 nC is at x₁ = 0 and charge q₂ = 3.00 nC is at x₂ = 2.00 m. At what point between the two charges is the electric field equal to zero?

Answer 1

Electric field at distace r due to charge q is given by

E=K q/r²  

Here we have two charges 1nc and 3nc and distance between them is 2 m .

let us consider at the x distace (towards right ) from 1nc charge the resultant electrec field or net electric field is zero.

for being it to be true

magnitude of Electric field at that point due to 1nc charge = Magnitude of electric field at that point due to 3nc charge

K(110^-9)/x² = K (310^-9) (2-x)²

1/x² =3/(2-x)²

(2-x)²=3x²

2-x =(3)x

2-x =1.73 x

2=1.73 x + x

2=2.73x

x=2/(2.73)

x=0.733 m right from the 1nc charge Ans