Chapter 7: Magnetism and Its Uses

Question 1

refers to the properties and interactions of magnets

Answer 1

magnetism

Question 2

a region of space that surrounds a magnet and exerts a force on other magnets and objects made of magnetic materials

Answer 2

magnetic field

Question 3

the regions of a magnet that exert the strongest force

Answer 3

magnetic poles

Question 4

groups of atoms with aligned magnetic poles

Answer 4

magnetic domains

Question 5

attractive or repulsive force between electric charges and magnets

Answer 5

electromagnetic force

Question 6

interaction between electric charges and magnets

Answer 6

electromagnetism

Question 7

a single wire wrapped into a cylindrical wire coil

Answer 7

solenoid

Question 8

a temporary magnet created when there is a current in a wire coil

Answer 8

electromagnet

Question 9

a device that uses an electromagnet to measure electric current

Answer 9

galvanometer

Question 10

a device that changes electrical energy into mechanical energy

Answer 10

electric motor

Question 11

the generation of an electric current by a changing magnetic field

Answer 11

electromagnetic induction

Question 12

uses electromagnetic induction to transform mechanical energy into electrical energy

Answer 12

generator

Question 13

a large wheel that rotates when pushed by water, wind, or steam

Answer 13

turbine

Question 14

electric current that is always in one direction through a wire

Answer 14

direct current

Question 15

electric current that reverses the direction in a regular pattern

Answer 15

alternating current

Question 16

a device that increases or decreases the voltage of an alternating current

Answer 16

transformer

Question 17

transformer voltage equation

Answer 17

output voltage (volts) / input voltage (volts) = turns in secondary coil / turns in primary coil

Vout/Vin = N2/N1

Question 18

magnets are surrounded by a ________ that exerts a ______ on all __________ __________.

Answer 18

magnetic field; force; magnetic materials

Question 19

magnet exerts force on…

Answer 19

other magnets

Question 20

atoms in magnetic materials behave like…

Answer 20

magnets

Question 21

in a permanent magnet, the magnetic domains remain aligned without…

Answer 21

an external magnetic field

Question 22

an electric current in a wire is surrounded by…

Answer 22

a magnetic field

Question 23

the electromagnet force is one of the…

Answer 23

fundamental forces

Question 24

magnetic field strength of an electromagnet can be controlled by:

Answer 24

changing the number of wire loops and by changing the current in the wire

Question 25

in a simple electric motor, an electromagnet rotates between the poles of a…

Answer 25

permanent magnet

Question 26

a changing magnetic field produces…

Answer 26

an electric current in a wire loop

Question 27

a generator transforms mechanical energy into…

Answer 27

electrical energy

Question 28

direct current is…

Answer 28

current in one direction

Question 29

alternating current changes direction in…

Answer 29

a regular pattern

Question 30

a transformer __________ or ___________ the voltage of an alternating current

Answer 30

increases; decreases