1. Using Electricity and Magnetism
1/2/2019 1:26 AM
Using Electricity and Magnetism
Chapter 21
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2. 21.1 What Is Electromagnetism?
An electric current produces a magnetic field.

3. 21.1 What Is Electromagnetism?
The magnetic field produced by a current has three characteristics.
The field can be turned on or off,
have its direction reversed,
or have its strength changed.

4. 21.1 What Is Electromagnetism?
An electromagnet is a strong magnet that can be turned on and off.

5. electromagnetism
The relationship between electricity and magnetism.

6. solenoid
A coil of wire with a current that acts as a bar magnet.

7. electromagnet
A magnet created by wrapping a coil of wire with a current around a ferromagnetic core.

8. 21.2 Electricity, Magnetism, and Motion
When a wire with a current is placed in a magnetic field, electrical energy is transformed into mechanical energy.

9. 21.2 Electricity, Magnetism, and Motion
Electric current is used to turn the pointer of a galvanometer

10. electric motor
A device that transforms electrical energy to mechanical energy

11. energy
The ability to do work or cause change.

12. electrical energy
The energy of moving electrical charges.

13. mechanical energy
Kinetic or potential energy associated with the motion or position of an object.

14. galvanometer
A device that uses an electromagnet to detect small amounts of current.

15. 21.3 Electricity From Magnetism
An electric current is induced in a conductor when the conductor moves through a magnetic field.

16. 21.3 Electricity From Magnetism
A generator uses motion in a magnetic field to produce an electric current.

17. electromagnetic induction
The process of generating an electric current from the motion of a conductor through a magnetic field.

18. direct current
Current consisting of charges that flow only in one direction in a circuit.

19. alternating current
Current consisting of charges that move back and forth in a circuit.

20. electric generator
A device that converts mechanical energy into electrical energy.

21. transformer
A device that increases or decreases voltage.

22. step-up transformer
A transformer that increases voltage.

23. step-down transformer
A transformer that decreases voltage.