Electric field in a rotating frame

In summary, the conversation discusses a scenario where a particle is moving in a circular path with uniform velocity in the presence of a radially pointing electric field. The question is whether the field felt in the rest frame of the particle will be constant or a superposition of two oscillating fields out of phase by π/2. The direction of the electric field and centrifugal force coincide with the radial direction in the approximation that the particle's speed is much smaller than the speed of light. However, if the speed of the particle is comparable to the speed of light, relativity must be taken into consideration. More information is needed to determine the orientation of the x and y axes in the rotating frame of reference.
  • #1
Malamala
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Hello! I have a radially pointing electric field i.e. at a given radius, R, the electric field has the same magnitude and points radially around that circle of radius R. I have a particle moving around that circle of radius R, with uniform velocity (ignore for now how it gets to move like that). What is the field felt in the rest frame of the particle (assume that z-axis is the same for the lab and particle frame)? Will it be a constant field always pointing along the same direction, or will it appear as a superposition of 2 oscillating fields, one in x the other in y direction, out of phase by ##\pi/2## (basically like an electric field rotating in the x-y plane in the frame of the particle)?
 
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  • #2
In the approximation that speed of the particle v << c, the direction of thus designed electric field, and centrifugal force in addition, coincide with r, the radical direction of the reference frame of rotation. If v is comparable to c, we must consider relativity and that might be messy.

Malamala said:
Will it be a constant field always pointing along the same direction, or will it appear as a superposition of 2 oscillating fields, one in x the other in y direction, out of phase by π/2 (basically like an electric field rotating in the x-y plane in the frame of the particle)?
To reply we may need more information how you set not r and ##\phi## but x-axis and y-axis in the rotating frame of reference.
 
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FAQ: Electric field in a rotating frame

What is an electric field in a rotating frame?

An electric field in a rotating frame refers to the electric field observed from a reference frame that is rotating with respect to an inertial frame. In such a frame, additional fictitious forces, such as the Coriolis force and the centrifugal force, must be taken into account when analyzing the behavior of charged particles and electric fields.

How does the rotation of a reference frame affect the observed electric field?

The rotation of a reference frame introduces fictitious forces that alter the observed electric field. Specifically, the Coriolis force affects the motion of charged particles, and the centrifugal force can create an additional potential that modifies the electric field. These effects must be considered to accurately describe the electric field in a rotating frame.

What is the Coriolis force, and how does it influence the electric field in a rotating frame?

The Coriolis force is a fictitious force that acts on moving objects within a rotating reference frame. It is proportional to the object's velocity and the angular velocity of the rotating frame. In the context of an electric field, the Coriolis force can alter the trajectories of charged particles, thus influencing the distribution and behavior of the electric field in the rotating frame.

Can Maxwell's equations be applied in a rotating frame?

Yes, Maxwell's equations can be applied in a rotating frame, but they must be modified to include the effects of the fictitious forces. The additional terms account for the influence of the rotating reference frame on the electric and magnetic fields, ensuring that the equations accurately describe the electromagnetic phenomena in the rotating context.

How do you transform the electric field from an inertial frame to a rotating frame?

To transform the electric field from an inertial frame to a rotating frame, you need to account for the relative motion between the two frames. This involves using the Lorentz transformation for electric and magnetic fields, along with additional terms to include the effects of the fictitious forces (Coriolis and centrifugal forces). The transformed electric field will reflect the combined influence of these factors in the rotating frame.

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