chapter 36: magnetism
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Chapter 36: Magnetism. Conceptual Physics Bloom High School Mr. Barry Latham, M.A.Ed. 36.1 Magnetic Poles. Magnets can attract and repel Like repels, unlike attracts Forces depend on distance I nverse square rule! - PowerPoint PPT PresentationTRANSCRIPT
CHAPTER 36:MAGNETISM
Conceptual PhysicsBloom High School
Mr. Barry Latham, M.A.Ed
36.1 Magnetic Poles Magnets can attract and repel
Like repels, unlike attracts Forces depend on distance
Inverse square rule! Magnetic North- on a magnets, one end seeks
the strongest north pole in the region Magnetic South- on a magnets, the other end
seeks the strongest south pole in the region Always exists in pairs of N-S, even if you break
the magnet in half!
36.2 Magnetic Fields Lab 93! PhET “Magnet &
Compass 2.05”
36.3 The Nature of a Magnetic Field
Magnetic field caused by moving charges
In a magnet, the electrons are always moving
When they spin on their axis all in the same direction, they produce a magnetic field! When they spin randomly,
they don’t produce any fieldThe Earth gets its magnetic
field from spinning too!
36.4 Magnetic Domains Magnetic domains- areas of a material that are
either aligned or unaligned to each other There is a degree of alignment
Non- not magnetic Partial- weak magnet Full- strong magnet
Creating Magnetic Domains
By putting a strong magnet near a non-magnet, it can cause the domains to align!
36.5 Electric Current & Magnetic Fields
Moving charges produce a magnetic field Section 36.3
When a current travels through a wire, a magnetic field is induced
Stronger current or more wires together Stronger magnetic field
PhET “Magnets & Electromagnets 2.05”
36.6 Magnetic Forces on Moving Charged Particles
A static charge will not interact with a magnetic field
A moving charge will be deflected by a magnetic field, though! Force is greatest when moving perpendicular to the
field lines Force is least when moving parallel
Magnetic field of Earth deflects most charged particles from the Sun and outer space
Aurora borealis is only seen near the poles, not the equator
March 5, 2010 ISS
36.7 Magnetic Forces on Current-Carrying Wires
Just as a single charge will be deflected by a magnetic field, a wire carrying a current will be deflected
The direction of the current will dictate the direction of deflection
36.8 Meters to Motors Galvanometer
Just as a compass aligns to a magnetic field, a dial can be made to do the same thing
Ammeter Galvanometer that measures current
instead of magnetic field strength Voltmeter
Galvanometer that measures voltage instead of magnetic field
Motors If we have an alternating current, then the
magnets will spin back and forth, trying to keep up with the frequency of voltage change
http://www.youtube.com/watch?v=it_Z7NdKgmY