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Investigate applications of magnetism and its relationship to the movement of electrical charge as it relates to• electromagnets• simple motors• permanent magnets• electromagnetic induction

Describe magnetism22

Magnetism is theforce of attraction or

repulsion due to electron motion.

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Magnets have two poles, a northpole and a south pole. Unlike magnetic poles attract each other, while like magnetic polesrepel each other.

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Groups of atoms with magnetic Groups of atoms with magnetic poles aligned are called magnetic poles aligned are called magnetic domains.domains.Materials Materials

with most with most of the of the domains domains lined up lined up are are considered considered magnetizedmagnetized..

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The more domains that are aligned, the stronger the magnetic field in the material.

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Field lines were introduced by michael faraday , who named them ‘’lines of force.’’

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Sketch this one

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Magnetism From Electricity A connection between electricity and magnetism was discovered (accidentally) over 100 years ago, it was noticed that a compass needle is deflected when brought into the vicinity of a current carrying wire. Thus, currents can induce a magnetic field. An electromagnetelectromagnet is simply a coil of wires which, when a current is passed through, generate a magnetic field, as below.

Electromagnet

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Current gives rise to magnetic fields, just as electric charge gave rise to electric fields

The basic idea behind an electromagnet is extremely simple: By running electric current through a wire, you can create a magnetic field.

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Electromagnets1111

Electricity through the coiled wire creates a magnetic field which induces magnetism in the iron core. The domains in the core become aligned with the magnetic field of the coil.

A rotating electromagnet is used in an electric motor to convert electrical energy to

mechanical energy.

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When a magnet is moved near a wire, an electric current can be created. This process is called electromagnetic electromagnetic inductioninduction. Electromagnetic induction is used in the operation of a generator, a device that converts mechanical energy to electrical energy. In a generator, an electric current is produced when a coil of wire is rotated in a magnetic field.

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Generating electricity:•coil of wire rotated in a magnetic field•magnet is moved near a wire

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July 3, 1977

The use of magnetic waves to make pictures of the inside of the body. Using a large magnet, radio waves, and a computer, an MRI produces two-dimensional and three-dimensional pictures.

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A Picture A: electric generator; Picture B:electromagnetB Picture A: electromagnet; Picture B: electric generatorC Picture A: electric motor; Picture B: electromagnetD Picture A: electric generator; Picture B: electric motor

Which of these

correctly identifies

both devices illustrated?

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A magnetic field can be found in which

of the following?A electric motorB sound waveC plastic cordD glass rod

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