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?

Answer 1

$\huge\underbrace\mathfrak\color{blue}Answer$

Answer 2

Answer:

the velocity

v

of the charged particle has a component parallel to the magnetic field

B

, instead of a circle, the resulting trajectory will be a helical path, as shown in figure. Because the velocity of the particle has a non-zero component along the direction of magnetic field

B