Magnetism
Name the 2 poles on a magnet.
North and South
Electricity is the flow of _______________.
Electrons
An electromagnet is a magnet created by an ___________________________.
Electric Current
Air (as sound waves)
Music stored on electronic devices, like MP3s, are an example of _____________ signals.
When two like poles are placed near each other, they will ________________.
Repel
An electric current is the path that electrons follow as they move through a circuit.
FALSE
An electric current is the FLOW of electrons through a circuit.
Electric Fields and Magnetic Fields act similarly with like poles repelling and unlike poles attracting and are invisible.
TRUE FALSE
True
Speakers use _________________ current to change the intensity and direction of the flow of electricity.
Alternating
The amount of stored energy an object has to do work is called _________________ energy.
Potential
The invisible force that surrounds a magnet is called a _______________________.
Magnetic Field
The movement of electrons through a copper coil creates a _______________________ around the coil.
Electric Field
The _________ of the electromagnet change when the direction of the current changes. This switches the direction of the forces in the field.
Poles
Changing the direction of the forces in the field moves the _____________ in different directions. This change causes different vibrations and sounds.
Coil
The energy used when an object is moving is called _______________ energy.
Kinetic
Which metal must an object have a significant amount of to display magnetic properties?
Iron
In a circuit, electrons flow from the ___________________ terminal to the _____________________ terminal.
Negative
Positive
Name the two ways to increase the strength of an electromagnet.
1. Create more coils of wire
2. Increase the strength of the power source
What part of the speaker vibrates and pushes the air away from the speaker?
Membrane
A human singing is an example of a(n) ANALOG DIGITAL signal.
Analog
Iron, Nickel, and Cobalt are considered _________________ materials because they have magnetic properties.
Ferromagnetic
Name the two types of electrical current.
Alternating Current (AC)
Direct Current (DC)
Name 2 uses of electromagnets in our everyday life.
1) Doorbell
2) Computers/Phones
3)MRI
4)Junkyard cranes
Name 5 key parts of a speaker.
1) Electrical/Power Source or Current
2) Wires
3)Coil
4)Magnet
5)Membrane
Radio Waves