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:
the correct answer is C +, – , +
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 +, – , +