Question

An electron moving with velocity v enters a constant magnetic field. What will its path through the field look like if it enters (a) parallel to the field direction? (b) perpendicular to the field direction? (c) at some other angle to the field direction?

Answer 1

force on electron inmagnetic field is F = q*v*B*sin(theta)

a) parallel to the field direction

theta = 0 degrees

F = q*v*B*sin(0) = 0 N

then the electron passes undeflectedly or undeviately or it continues its original path

b) perpendicular to the field direction ,theta = 90 degrees

F = q*v*B*sin(90) = q*v*B

Now the electron takes the circular path

c) at some other angle to the field direction

the electron takes spiral motion ( combination of circular and linear motion)