Question

An infinite plane metallic sheet having surface charge density ‘+σ’ is placed in vacuum. P is a point at a small distance ‘r’ to its right.

1. Write an expression for intensity of electric field at point P.
2. Now, an identical charged sheet having surface charge density ‘−σ’ is placed parallel to the first sheet such that the point P is to its left at the same distance ‘r’. (The point P lies between the two plates.)
   1. What is the resultant intensity of electric field at point P?
   2. What is its direction?

Answer 1

i. Intensity of electric field at point P is:

E = `sigma/(2 epsilon_0)`

ii. (a) The resultant intensity of electric field atpoint P, will be:

E = `sigma/epsilon_0`

(b) The direction will be from +σ to −σ.