# Electrostatics and magnetism

Let a square loop be placed in a uniform electric field in a position of stable equilibrium.

Then, because of the electric field, if the electric field is in the rightward direction then a positive charge will be developed in the rightward direction and negative charges will be developed in the leftward direction. Thus an emf is generated between the left side and right side points; so a magnetic field is induced in it and it will interact with the electric field.

Interaction means force, so why do we say that no force acts on a square loop when placed in a uniform electric field?

• A time-varying magnetic field induces an emf in a loop, not the other way around (and even here, there is no net emf around the loop). It is not clear what you mean by "[the magnetic field] will interact with the electric field".
– AV23
May 5 '15 at 17:00
• Doesn't equilibrium mean the net force is 0? I don't think it is applicable to talk about individual forces, but over all there wouldn't be a force on the loop. May 5 '15 at 17:43
• @AV23 you're wrong about the loop comment. Maxwells equations without currents: curl(E) = -dB/dt, curl(B) = (1/c^2) * dE/dt Dec 22 '15 at 6:50
• @aquirdturtle Ok. I guess what I should have written is a simple emf between two points does not generate a time-varying magnetic field.
– AV23
Feb 7 '16 at 17:22