A uniform magnetic field of magnitude is directed vertically upward
PHYSICS · Subjective · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism
Problem
A uniform magnetic field of magnitude 1.2T is directed vertically upward. From the same point at ground level, a proton (mp,q=+e) and an α-particle (m=4mp,q=+2e) are projected horizontally toward the east with equal kinetic energies of 2.0MeV each.
(i) For each particle, state whether its circular motion, as viewed from above, will be clockwise or anticlockwise. Justify your answer.
(ii) Obtain a general expression for the radius R of the circular trajectory in terms of the particle’s mass m, charge q, kinetic energy K, and the magnetic field B. Hence calculate the radii for the proton and for the α-particle.
(iii) Which of the two particles will return to the launch level first? Support your answer with quantitative reasoning.