Question

Consider the motion of a charged particle in a uniform magnetic field directed into the paper. If velocity v of the particle is in the plane of the paper the charged particle will ______.

Options

• describe a hyperbola

• describe a circle

• describe an ellipse

• describe a straight line

Answer 1

Consider the motion of a charged particle in a uniform magnetic field directed into the paper. If velocity v of the particle is in the plane of the paper the charged particle will describe a circle.

Explanation:

The charged particle experiences magnetic Lorentz force given by `vec"F" = "q"(vec"v" xx vec"B")`.

This force acts perpendicular to the velocity vector in the plane of the paper at all places on the plane. The magnetic Lorentz force works like a centripetal force on the particle, causing it to move in a circle.