Question

two charges of +5×10 C and +20×10 C are separated by a distance of 2m .Find the point on the line joining them at which electric field intensity is zero

Answer 1

Answer: 0.66 from 5×10C and 1.34 from 20×10C

Explanation:

Let x be the distance from the charge 5× 10C and 2-x is the distance from 20×10C.

Kq1/x^2 = kq2/(2-x)^2

5×10/x^2 = 20×10/(2-x)^2

1/x^2 = 4/(2-x)^2

(2-x)^2= 4x^2

2-x = 2x

3x =2

x = 2/3

x = 0.66

Therefore 0.66 from 5×10.

2-x = 2-0.66=1.34 from 20×10