# Does the electric field change due to rotation

1. Oct 11, 2009

### dragonlorder

Suppose you have a ring of charge and they cant move around. and you spin it, of course, we will have current. What about the electric field of the ring, the current indicates that there's electric field going around the ring.But Gauss's law kind of suggest, the electric field is the same as when it is at rest (The enclosed charge is the same). But when it is at rest, the field just points straight out/in.

2. Oct 11, 2009

### kanato

Regardless of how fast it's spun, the charge distribution will be constant, so the E field will be the same. If you spin it at constant velocity, then the current will be constant, and you will have a constant B field. If the rotational velocity of the ring changes, then the changing B field will induce a change in the E field which just adds linearly with the E field from the charge distribution.

3. Oct 12, 2009

### dragonlorder

Ah, so Gauss Law indicates that the magnitude is the same if moves at constant velocity. But the direction of the field lines would be bent depends on which frame of reference you are in