Question: When a charged particle of mass m and charge q is fired into a perpendicular magnetic field B with a speed v, it is drawn into a circular path of radius r=mv/qB. Astronomers have detected electromagnetic radiation at a frequency of 45 MHz from a distant interstellar gas cloud. They think it is due to electrons moving in circular paths in a magnetic field. If so,
A- What is the magnitude of the magnetic field?
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