Show:
Magnets and Magnetism 1
Magnets and Magnetism 2
Magnetism from Electricity
Electricity from Magnetism
Potpourri
100
Any material that attracts iron
What is a magnet
100
Magnetic poles are always in _____________
pairs
100
the study of the interaction between electricity and magnetism
What is electromagnetism
100
What did Faraday and Henry discover?
That you a magnetic field can induce or create an electric current.
100
A device that increases or decreases the voltage of alternating current.
What is a transformer
200
What 3 properties do all magnets have?
1) They have a north pole and a south pole 2) They exert a force 3) They are surrounded by a magnetic field
200
In magnetic forces, like poles ______________ and opposite poles ______________
Like poles repel (push apart) and opposite poles attract (stick together)
200
A coil of wire that produces a magnetic field when carrying an electric current.
What is a solenoid
200
The process by which an electric current is made by changing a magnetic field
What is electromagnetic induction
200
What causes an aurora or "northern lights"?
An aurora is formed when charged particles from the sun hit oxygen and nitrogen in the air.
300
The region around a magnet where the magnetic force can act
What is a magnetic field
300
Tiny groups of charged atoms inside iron.
What are domains
300
A coil of wire wrapped around an iron core
What is an electromagnet
300
This machine uses electromagnetic induction to change mechanical energy into electrical energy.
What is an electric generator
300
What do scientists think causes the Earth's magnetic field?
The movement of electric charges in the Earth's core.
400
What makes something magnetic?
The domains in the object must be aligned or lined up.
400
What happens when you cut a magnet into 2 pieces? Why?
Each piece will have a north pole and south pole because the domains inside the magnet re-align.
400
What is an electric motor?
A device that changes electrical energy into mechanical energy.
400
Faraday's experiment demonstrated that the ___________ current was made only when the _______________ field was changing.
What is electric current and magnetic field
400
What are 4 ways for a magnet to lose it's magnetism?
1) drop the magnet 2) putting the magnet in a strong magnetic field 3) Increasing the temperature 4) hitting the magnet all of them make the domains inside the magnet lose alignment.
500
Name 2 kinds of magnets and what they are made of.
1) ferromagnets are made of iron, cobalt, nickel 2) electromagnets are made from a magnet and an electric current
500
Why does a compass needle point north?
Because the magnetic pole closest to the geographic north pole is the magnetic south pole.
500
What 2 ways can you increase the power of an electromagnet?
By increasing the number of loops of wire around the solenoid and increasing the current.
500
Explain the 3 steps of how an electric generator works
1) A crank is turned rotating the wire coil through the magnetic field 2) This creates an electric current in one direction. 3) As the coil continues to rotate, the electric current continues in the opposite directin.
500
Explain the difference between a step-up and a step-down transformer.
A step-up transformer increases voltage and has more coils of wire in the secondary coil. A step-down transformer decreases voltage and has more coils on the primary coil.