checkpoint_12_magnetism

Magnetism

Magnetic Forces

Three points are lcated in a uniform magnetic field as shown. The [B] field points into the screen.

1)

A positively charged particle is located at point [A] and is stationary. The direction of the magnetic force on the particle is:

• Zero
  • the charge is not moving

2)

The positive charge moves from point [A] toward [B]. The direction of the magnetic force on the particle is:

• Left
  • Point your fingers from [A] to [B] and curling in the direction of magnetic field we find the force on the particle is pointing left.

Motion in a Magnetic Field

The drawing below shows the top view of two interconnected chambers. Each chamber has a unique magnetic field. A positively charged particle is fired into chamber 1, and observed to follow the dashed path shown in the figure.

1)

What is the direction of the magnetic field in chamber 1?

• out of the into the screen
  • know the direction of the velocity and the force which is being exerted on the charged particle we find able to use the right hand rule by pointing the thumb in the direction of the force, point the figures toward the initial velocity and then identifying where the fingers curl toward.

2)

Compare the magnitude of the magnetic field in chamber 1 to the magnitude of the magnetic field in chamber 2.

• [|B_1| > |B_2|]
  • The arch of the particle path appears to be larger in the second chamber.