Question

Write the expression for Lorentz magnetic force on a particle of charge ‘q’ moving with velocity \(\overrightarrow{V}\) in a magnetic field \(\overrightarrow{\text{B}}\). Show that no work is done by this force on the charged particle.

Answer 1

Lorentz magnetic force, \(\overrightarrow{F_m}=q\overrightarrow{v}\times\overrightarrow{B}\)

Work done,

As \((\overrightarrow{v}\times\overrightarrow{B}).\overrightarrow{v}=0\)

∴ Work, W = 0