A singly charged positive ion moves in a circular path of radius in a uniform…
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A singly charged positive ion moves in a circular path of radius r in a uniform magnetic field B, its velocity being perpendicular to the field. The magnetic field is then reduced to 2B while simultaneously the kinetic energy of the ion is increased to four times its initial value.
(i) Calculate the new radius of the path in terms of r.
(ii) Find the ratio of the new frequency of revolution to the original frequency.