p12 electromagnetic waves

Question 1

carrier waves

Answer 1

waves used to carry any type of signal

Question 2

charge-coupled device (CCD)

Answer 2

an electronic device that creates an electronic signal from an optical image formed on the CCD’s array of pixels

Question 3

contrast medium

Answer 3

an X-ray absorbing substance used to fill a body organ so the organ can be seen on a radiograph

Question 4

electromagnetic spectrum

Answer 4

the continuous spectrum of electromagnetic waves

Question 5

microwaves

Answer 5

electromagnetic waves between infrared radiation and radio waves in the electromagnetic spectrum

Question 6

optical fibre

Answer 6

thin glass fibre used to transmit light signals

Question 7

radiation dose

Answer 7

amount of ionising radiation a person receives

Question 8

radio waves

Answer 8

electromagnetic waves of wavelengths greater than 0.10m

Question 9

ultraviolet radiation (UV)

Answer 9

electromagnetic waves between visible light and X-rays in the electromagnetic spectrum

Question 10

wave speed

Answer 10

the distance travelled per second by a wave crest or trough

Question 11

white light

Answer 11

light that includes all the colours of the spectrum

Question 12

x-rays

Answer 12

electromagnetic waves smaller in wavelength than ultraviolet radiation than ultraviolet radiation and produced by X- ray tubes

Question 13

electromagnetic waves

Answer 13

electromagnetic waves are transverse waves that transfer energy from the source of the waves to an absorber

Question 14

how is the electromagnetic spectrum grouped

Answer 14

in terms of their wavelength and their frequency. Going from long to short wavelength (or from low to high frequency) the groups are: radio, microwave, infrared, visible light (red to violet), ultraviolet, X- rays and gamma rays.

Question 15

the waves in the electromagnetic spectrum starting from longest wavelength and lowest frequency

Answer 15

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

Question 16

properties of electromagnetic waves

Answer 16

• Different substances may absorb, transmit, refract or reflect electromagnetic waves in ways that vary with wavelength.
• Some effects, for example refraction, are due to the difference in velocity of the waves in different substances.

Question 17

properties of radio waves

Answer 17

• Radio waves can be produced by oscillations in electrical circuits.
• When radio waves are absorbed they may create an alternating current with the same frequency as the radio wave itself, so radio waves can themselves induce oscillations in an electrical circuit.

Question 18

uses of radio waves

Answer 18

television and radio

Question 19

uses of microwaves

Answer 19

satellite communications and cooking food

Question 20

uses of infrared waves

Answer 20

electrical heaters, cooking food, infrared cameras

Question 21

uses of visible light

Answer 21

fibre optic communications

Question 22

uses of ultraviolet waves

Answer 22

energy efficient lamps, sun tanning

Question 23

x-rays and gamma rays

Answer 23

medical imaging and treatments

Question 24

wave speed equation

Answer 24

wave speed = frequency x wavelength