# Homework Help: Need Jump Start On Two EM Questions

1. Apr 16, 2007

### mochi_melon

1) I am asked to find the rate of radiation emitted from a charged particle with constant velocity moving through a magnetic field at an angle and then with an added parallel electric field. I know how to do it without the fields and just the point charge, I just don't know how to factor in the particle going through an E and B field.

However, I am inclined to believe that there is no radiation due just from the point charge because it is a constant velocity, making all the radiation from the field(s) it is in. Is this correct? Would the radiation just be the Poynting vector in that case (but if so, then it'd be zero before the addition of the parallel E field because you're taking the cross product of all zeros on the one side)

2) I am also asked to find the first non-zero multiple moment of a system for another problem (loop of radius r with alternating current). I'm not really sure what they mean by that, I have attached the formula for the magnetic moment, but I'm not sure what they mean by non-zero multiple.

Thanks!

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