Find the period of revolution of an electron having a kinetic energy of 1.5 MeV in a magnetic field with induction 0.02 T. The electron moves in a plane perpendicular to the lines of force.

Answer

7ns

Explanation

This is a relativistic electron, since its tolal energy `epsi=epsi_(0)+ K= 0.511 + 1.5 =2.0 MeV` is much greater than its rest energy.
We obtain from `mu^2//R= euB`
`T=(2piR)/(u)=(2pim)/(e B)=(2pi epsi)/(e Bc^2)`