Question

How does a steady magnetic field affect the velocity of moving charged particle when the velocity is perpendicular to the magnetic field?

Answer 1

We know that when a moving charge enters in a uniform(steady) magnetic field then it experiences a force.Magnitude of this force is given by:

F=qvBsinα

Where:q=charge,v=speed,B=magnetic field, α=angle b/w magnetic field and velocity of charge

Direction of this force is calculated by using Fleming's left hand rule.

In the above problem, the velocity of charge is perpendicular to the magnetic field(α=90°).So By flemings left hand rule, the direction of force on charge comes to be perpendicular to the velocity. And we know that when something experiences a force that is perpendicular to the velocity then that body(charge) moves in a circular path.

Hence our charge will move in a circular path and the radius of this circular path will be directly inversly propotional to the value of magnetic field.