A mono energetic electron beam with electron speed of 5.20×106ms−1 is subjected to a mognetic field of 1.30×10−4T , normal to the beam velocity .What is the radius of the circle traced by the beam , given em for electron equals 1.76×1011ckg−1Is the formula you employ valid for calculating radius of the path of 20 Mev electron beam ? If not in what way is it modified ?