Question

A uniform electric field is present in the region between infinite parallel plane plates A and B and a uniform electric field is present in the region between infinite parallel plane plates B and C. When the plates are vertical, is directed to the right and to the left. The signs of the charges on plates A, B and C may be:_______.

A. -- ,--, --
B. + , -- , --
C. + , --, +

Answer 1

the correct answer is C +, - , +

Step-by-step explanation:

The electric field for positive charges is outgoing and for negative charges it is directed towards the charge.

Let's apply this to our case:

On plates A and B the field goes to the right, therefore plate A must be positive

In plates B and C the way it goes to the left, so the field is selected from it, this implies that plate C is positive

therefore plate B must be negative for both cases

when checking the correct answer is C +, - , +