Figure 22-1 The Force Between Two Bar Magnets

Figure 22-2 Magnets Always Have Two Poles

A magnet creates a magnetic field in its vicinity. Magnetism Magnetic field- A magnet creates a magnetic field in its vicinity.

Magnetism It represents the effect a magnet has on its surroundings.

Magnetism All magnetic fields arise from the motion of electric charge.

Magnetism A magnetic field is represented by the symbol

Magnetism Magnetic field lines can be used to represent magnetic fields. The closer the lines are together, the greater the magnitude of the vector

Figure 22-4 Magnetic Field Lines for a Bar Magnet

The direction of a magnetic field Magnetism The direction of a magnetic field at a given location is the direction in which the north pole of a compass points when it is placed in that location.

Figure 22-7 The Magnetic Force on a Moving Charged Particle

Example 22-1 A Tale of Two Charges

Magnetism A charged particle moving in a magnetic field will experience a force if it has a velocity component perpendicular to the magnetic field.

Magnetism

The Magnetic Force Right Hand Rule (RHR) Magnetism The Magnetic Force Right Hand Rule (RHR)

Magnetism

Figure 22-8 The Magnetic Force Right-Hand Rule

Figure 22-9 The Magnetic Force for Positive and Negative Charges

Conceptual Checkpoint 22-2 Which is the positive? Negative? Zero charge?

Magnetism A charged particle moving with a velocity perpendicular to a uniform magnetic field, will move in a circle.

Magnetism Forces on a long straight current carrying wire in a magnetic field.

Magnetism Forces on a long straight current carrying wire in a magnetic field.

Magnetism A long straight current carrying wire has charges moving inside it.

Magnetism If it is placed in a magnetic field, it will experience a force

Magnetism

Magnetism

Figure 22-15 The Magnetic Force on a Current-Carrying Wire

Magnetism Direction of magnetic forces in a current carrying loop in a magnetic field.

Figure 22-16 Magnetic Forces on a Current Loop

Example 22-5 Torque on a Coil

Magnetism

Magnetism

Magnetism To calculate the magnitude and direction of the magnetic field in the vicinity of a long straight current carrying wire.

Magnetism Apply the magnetic field right hand rule. Point your thumb in the direction of current flow. Curl your fingers around the wire They will point in the direction of the magnetic field.

Figure 22-19 The Magnetic Field of a Current-Carrying Wire

Magnetism

The number of magnetic field lines that cross an area. Magnetism Magnetic flux The number of magnetic field lines that cross an area.

Figure 23-3 The Magnetic Flux Through a Loop

Example 23-1 A System in Flux

Magnetism Magnetic flux

Magnetism Faraday’s Law

Conceptual Checkpoint 23-1 Which flux(es) change(s) with time?

Magnetism Lenz’s Law An induced current flows in a direction that opposes the change that caused the current.

Conceptual Checkpoint 23-2 How do the accelerations compare?