Question

An electron and a proton move in circular orbits in a planeperpendicular to a uniform magnetic field b. (a) find the ratio of the radii of theircircular orbits when the electron and the proton have the samekinetic energ

Answer 1

it does not depend on the velocity of the particle and electric field made you work on a charged particle while a magnetic field does no work this is typical of uniform circular motion

Answer 2

An electron and a proton move in circular orbits in a plane perpendicular to a uniform magnetic field B. ... b)Find the ratio of the radii of their circular orbits when the electron and the proton have the same kinetic energy.