Magnetic Fields September 30, 2013 October 2, 2013

Magnetic Fields

September 30, 2013

October 2, 2013

The Force Between Two Bar Magnets

Origins of Magnetism

Magnetic Domains

• What would happen if you cut the magnet in half (between the north and south poles)?

Inside Permanent Magnets (and Ferromagnetic Materials)

Magnets Always Have Two Poles

Magnetic Field of a Bar Magnet

Thought Questions

• Do you notice anything strange about the direction of the field lines? Which way does the compass point?

• Draw field lines for the Earth’s magnetic field.

Magnetic Field of the Earth

Magnetic Field Lines Using Iron Filings

Continuity of Field Lines

Magnetic Field produced by a Current-Carrying Wire

Direction for 3-D in 2-D

Which way does the current flow?

Where is the magnetic field strength the greatest?

The Solenoid

Effects of Magnetic Fields on Charged Particles

The Magnetic Force for Positive and Negative Charges

The Magnetic Force on a Moving Charged Particle

What Direction is the Force?

What are the Different Charges?

Differences Between Motion in Electric and Magnetic Fields

Circular Motion in a Magnetic Field

Magnetic Force on a Current-Carrying Wire

The Magnetic Force on a Current-Carrying Wire

The Magnetic Force Between Current-Carrying Wires

The Magnetic Force Between Current-Carrying Wires

Group Discussion

• Walker, Chapter 22 (pp. 742-743)

• Conceptual Questions:– Questions 2-10 and 17-21

• Groups of three:– “Concept artist” to draw fields– “Recorder” to record answer & explanation– “Reporter” to report findings at the end of class

Applications of Magnetic Fields

The Mass Spectrometer

Velocity Selectors / CRTs

Magnetic Levity

Motion in a Magnetic Field

Helical Motion in a Magnetic Field

Uranium Separation Using a Mass Spectrometer

Velocity Selectors

Cathode Ray Tube

Magnetic Levity

Magnetic Trains