Chapter 11, Problem 10RQ

Both gravitational and electrical forces act along the direction of the force fields. How is the direction of the magnetic force on a moving charge different?

To determine

The direction of the magnetic force on a moving charge.

Answer to Problem 10RQ

The direction of the magnetic force on a moving charge is always perpendicular to the magnetic field lines.

Explanation of Solution

A charged particle at rest does not respond to magnets. But when moving, the charged particles experience a deflecting force. This force is greatest when the particles move at right angles to the magnetic field lines. At other angles, the force is less and becomes zero when the particle moves parallel to the lines.

The force is always perpendicular to the magnetic field lines as well as the velocity of the charged particles.

Conclusion:

Therefore, the direction of the magnetic force on a moving charge is always perpendicular to the magnetic field lines.