Question

Two large thin plane sheets, each having surface charge density σ. are held close and parallel to each other in air. What is the net electric field at a point

1. inside and
2. outside, the sheets?

Answer 1

For two large, parallel thin sheets with identical surface charge density σ in air, the net electric field is:

1. Inside (between) the sheets: The net electric field is zero. because the fields from each sheet `(E = sigma/(2 epsilon_0))` are equal and point in opposite direction. Hence (E = 0).
2. Outside the sheets: The net electric field is `sigma/epsilon_0`(pointing away from the sheets) as the fields from both sheets are equal and act in the same direction.