# The electric field at a small distance R from an infinitely long plane sheet is directly proportional to A. R2/2 B. R/2 C. R-2 D. none of these

Arun
25750 Points
3 years ago
Dear student

Electric field at a distance from an infinite conducting sheet carrying uniform charge density is given by 2ε0σ. Thus, it is independent of r.
Vikas TU
14149 Points
3 years ago

The field of a point charge, or a finite shaped charge, diverge as these proceed away from the charged object. This divergence in the field lines makes the filed weaker as you move away from the charge. But once, the charged object is an infinite plane sheet, the field lines can't diverge, because if they do, they would be intersecting each other ( A violation of the laws of physics). And since, the field lines are parallel, they are uniform, which means, they would not depend on the distance from the plane.

But there is one more way of explaining this: Imagine you have a round light bulb. Obviously, the light rays coming from this bulb would nbe diverging. Now, suppose you have a very large sheet which emits light just like your bulb. How would the light coming out from this sheet behave? Yes, the light rays would be parallel to each other. That is, the intensity of light from this large sheet would remain the same as you go farther from thus sheet. This analogy works for the filed coming from the infinitely large charged sheet/plane.