Imagine a charge (I'm talking about CLASSICAL charges, NOT electrons in an atom) which is orbiting amother much more massive charge. The charge will radiate, call the power it radiates p. Now imagine a charge spinning on it's axis (but not orbiting, just spinning), it will also radiate(we can divide the charge into small chunks, these chunks are accelerating, so they radiate), call the power q. Now if the charge is BOTH orbiting another charge and spinning on it's axis (with the same angular velocity), will the radiated power be p+q? If not, when will it be at least approximately p+q? Will the radiated power depend of the tilt of the axis of the charge?

Follow up question: Can we talk about the instantaneous power that a charge is radiating, or can we only talk about average power? Why or why not?

The spinning charge will not radiate, because the electric and magnetic field will be constant and time independent. Or yor may say that the radiation from different "chunks" will cancel each other.

Of course we can speak about the instant power.

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Now, if we consider the charge both orbiting and spinning, then the radiated power will be different, because you will have an oscillating quadrupole magnetic moment. If their frequency are not harmonics, then we can average the radiated power separetely.

shyboy said:
The spinning charge will not radiate, because the electric and magnetic field will be constant and time independent. Or yor may say that the radiation from different "chunks" will cancel each other.