Electromagnets Generators Motors

Induction, generators & motors

Magnetism and Electric Current

⚫ A solenoid is a coil
of wire with an
electric current in
it.

⚫

The electric
current creates a
magnetic field
around each loop of
the wire.

◼

more loops = more
magnetic force

◼

more current =
more magnetic
force

Magnetism and Electric Current

⚫
The magnetic
force of a solenoid
can also be
strengthened by
adding a soft iron
core to its center.

⚫

This is called an
electromagnet.

Multiple Choice

All electric current generate ___ fields

• Thermal

• magnetic

• Radio

• Kinetic

Multiple Select

To increase the power of an electromagnet you can (more than one answer)

• increase the current

• increase the number of metal coils

• Decrease the current

• decrease the number of turns

Creating Electric Current

⚫
Faraday’s Lawof
Induction describes
the production of a
current in a
conducting circuit by
a change in the
strength, position, or
orientation of an
external magnet.

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Multiple Choice

In 1831, Michael Faraday was the first to realize that an electric current could be induced by passing a magnet through a coil of copper wire. Which factor is MOST essential for the induction of the electric current?

• The use of strong magnets for the process

• The movement of the magnet relative to the coil

• The use of very long coils for the process

• The use of magnetic material to make the coil.

Creating Electric Current

⚫
Electrical generators change mechanical
energy to electrical energy using
electromagnetic induction.

In a commercial generator, an electric current is
produced when a large coil of wire is rotated
through a strong magnetic field.

Using Electric Current

⚫
Electric Motors
convert electrical
energy into
mechanical energy by
using magnets to
create motion.

⚫

Inside an electric
motor, the
attracting and
repelling forces of
two magnets create
a rotational motion.

• A generator is a device that converts mechanical energy into electrical energy.

• Most of the electrical energy we use comes from generators

​​Generators

• Electric motors convert electrical energy into mechanical energy that is used to do work. Examples of motors include those in many household appliances, such as blenders and washing machines

Motors

Multiple Choice

Fields can exist that exert force on objects, even when objects are not touching.

• True

• False

Multiple Choice

Current produced when a coil of wire is moved

through a magnetic field

• Circuit

• Electromagnetic Induction

• Solenoid

• Electric Motor

Multiple Choice

Which of the following DOES NOT have an effect on the strength of magnetic and electric charge?

• Amount of resistance in a material

• Size or loops of a solenoid

• Increased current

• Amount of neutrons in an atom.

Multiple Choice

_________ produce temporary magnetic fields while ________ have permanent magnetic fields

• Permanent Magnets, Electromagnets

• Electromagnets, Permanent Magnets

• Electromagnets, Currents

• Permanent Magnets, Solenoids