VISUAL PHYSICS ONLINE

6 ELECTROMAGNETISM

P60 005

(A)

A positively charged particle is moving with velocity v in a magnetic field. At this moment, what is the direction of the force on the positively charged particle? Explain. Describe the subsequent motion of the particle.

(B)

A charged non-magnetic particle is moving in a magnetic field. What would NOT affect the magnetic force on the particle?

(B1) The strength of the magnetic field.

(B2) The magnitude of the charge on the particle.

(B3) The velocity component parallel to the magnetic field direction.

(B4) The velocity component perpendicular to the magnetic field direction.

Explain each alternative.

View solution below only after you have completed the answering the question.

Solution

(A)

Right hand screw rule – force on positive charge is directed towards the right. The magnetic force acting on the positive charge will always act towards the centre of a circle – the electron will move in a circular path.

(B)

Force on a moving charge in a magnetic field

The force only depends on the component of the velocity which is at right angles to the magnetic field. It does not dependent on the parallel component of the velocity.