Chapter 20-22 study guide

Question 1

commutator

Answer 1

a structure in DC motors and generators that converts current between DC and AC.

Question 2

electromagnets

Answer 2

The combination of a strong magnet and an electrified wire coil.

Question 3

Generator

Answer 3

a device that converts mechanical energy into electrical energy by electromagnetic induction.

Question 4

magnetic domain

Answer 4

a group of atoms whose individual magnetic fields are aligned.

Question 5

magnetic field

Answer 5

The region surrounding a magnet or a current-containing wire can apply a magnetic force on magnetic materials.

Question 6

magnetic pole

Answer 6

one of the two regions of concentrated magnetic fields in a magnet is called the north and south.

Question 7

solenoid

Answer 7

a coil of current-carrying wire used as a magnet.

Question 8

A transformer

Answer 8

a device that uses electromagnetic induction to increase or decrease the voltage of an AC.

Question 9

gamma ray

Answer 9

a high-energy photon that is emitted from a nucleus when a radioactive isotope experiences gamma decay

Question 10

infrared waves

Answer 10

An electromagnetic wave that is just below red visible light and is used in astronomy, medical imaging, and wireless devices

Question 11

microwaves

Answer 11

a wave from the upper end of the radio wave band used for navigation, communication, and cooking.

Question 12

radio waves

Answer 12

the longest and lowest energy type of electromagnetic wave; used for navigation and communication

Question 13

ultraviolet waves

Answer 13

an electromagnetic wave that is just beyond violet visible light used for medical treatment dentistry and killing bacteria

Question 14

visible light

Answer 14

an electromagnetic wave that humans can see

Question 15

x rays

Answer 15

A form of electromagnetic energy with wavelengths between 10 nm and 10 nm that is used for medical imagery, transportation, security, and nondestructive inspection

Question 16

speed of light

Answer 16

c= 3x10^3 meters per second

Question 17

luminous object

Answer 17

an object that is producing visible light

Question 18

diffuse object

Answer 18

the reflection off a rough or uneven surface that reflects light in all directions.

Question 19

opaque

Answer 19

a material through which visible light can not pass

Question 20

specular reflection

Answer 20

occurs when surface reflections on a smooth surface mostly in the same direction

Question 21

translucent material

Answer 21

A material through which light passes, but the light is scattered and does not transmit a clear image.

Question 22

transparent material

Answer 22

a material through which light passes without scattering transmitting a clear image

Question 23

primary color

Answer 23

One of the three colors, red, blue, and green, of visible light that humans can see, if mixed, can create more colors.

Question 24

incident ray

Answer 24

a light ray approaching a surface, an incoming ray.

Question 25

C= ^ F

Answer 25

C= ^ F

Question 26

5.

Answer 26

radio waves, microwaves, infrared waves, visible light, ultraviolet waves, x rays and gamma rays

Question 27

effects of heating a magnet

Answer 27

weakens the magnetic field.

Question 28

effects of a strong magnetic domain

Answer 28

makes the magnetic field stronger

Question 29

ways to make a greater magnetic field

Answer 29

add more wire coils and shorten the distance.

Question 30

how electrical generators produce Ac power

Answer 30

use a commutator to switch the current.

Question 31

why do generators need to be able to rotate

Answer 31

to use up all of the energy

Question 32

relationship of frequency, wavelength, and energy

Answer 32

to find speed of waves

Question 33

How the electric and magnetic fields are arranged in an electromagnetic wave

Answer 33

They are interviewed.