Question

Three infinite planes of charge, A, B and C, are vertical and parallel to one another. There is a uniform electric field to the left of plane A and a uniform electric field to the right of plane C. The field points to the left and the field points to the right. The signs of the charges on plates A, B and C may be
Select one:
a. +, -, -.
b. any one of the above.
c. +, +, +.
d. +, -, +.
e. -, -, -.

Answer 1

help will be appriciated

Answer 2

Please help

Answer 3

If i understand it correctly, the field in the left side of A is pointing in the left and that in the right side of C is pointing towards right.
In that case, A and C is both positive charged. Because electric field always points to positive to negative charge.
And for B, it can be both if all the plates are in equal distance. Because in that case the system will be in stable equilibrium.
So (c) and (d) is equally correct.

Answer 4

correction on the last line.
The system will be in an unstable equilibrium.
And still (c) and (d) is correct.