An electron with charge -e and mass m travels at a speed v in a plane perpendicular to a magnetic - Physics - Magnetism And Matter

Question

An electron with charge -e and mass m travels at a speed v in a
plane perpendicular to a magnetic field of magnitude B The electron
follows a circular path of radius R In a time, t, the electron
travels halfway around the circle What is the amount of work done
by the magnetic field?

Debalina Deb · Accepted Answer

Dear student,
<img alt="" src=
"https://s3mn%20mnimgs%20com/img/shared/content_ck_images/ck_5fba658dbb9d2%20jpg"
style="width: 1022px; height: 650px;">
hence workdone by magnetic field =0
[note:
in a circular path, velocity is always tangential, so as
displacement
and when electron enters with velocity perpendicular to B, using
right hand screw rule, we can predict, lorentz force acts towards
the centre ]
Regards,

An electron with charge -e and mass m travels at a speed v in a plane perpendicular to a magnetic field of magnitude B. The electron follows a circular path of radius R. In a time, t, the electron travels halfway around the circle. What is the amount of work done by the magnetic field?