ElectroMagnegnetic Waves COPY

Question 1

Recite the electromagnetic spectrum in order of decreasing wavelength

Answer 1

Radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, x rays and gamma rays

Question 2

What type of wave has the lowest frequency and energy, but largest wavelength

Answer 2

Radio waves

Question 3

What do electromagnetic waves form

Answer 3

A continuous spectrum

Question 4

Where do all types of electromagnetic waves travel at the same speed

Answer 4

All types of electromagnetic waves travel at the same speed through a vacuum (space)

Question 5

What is the range of the wavelengths of the electromagnetic spectrum?

Answer 5

From 10^(-15) to 10^(4) metres

Question 6

What type of light contains all the colours of the visible spectrum

Answer 6

White light contains all the colours of the physical spectrum

Question 7

What do we use infrared radiation for

Answer 7

Carrying signals from remote handsets and inside optical fibres

Question 8

What do we use microwaves for

Answer 8

Carrying satellite TV programmes and mobile phone calls

Question 9

What do we use radio waves for

Answer 9

Radio and TV broadcasting, bluetooth

Question 10

What is a danger with infrared radiation

Answer 10

Exposure can cause skin burns

Question 11

What can exposure to ultraviolet cause

Answer 11

Skin cancer and blindness

Question 12

What are x rays used for

Answer 12

Medical imaging

Question 13

What are gamma rays used for

Answer 13

To kill harmful bacteria in food, to sterilise surgical equipment and to kill cancer cells

Question 14

What and when do x rays and gamma rays damage

Answer 14

X rays and gamma rays damage living tissue when they pass through it

Question 15

What are x rays used for in hospitals

Answer 15

To diagnose some medical conditions, for examiner in computed tomography (CT) scanning, bone fractures and dental problems. X rays are also used to treat some conditions, for example in killing cancer cells

Question 16

What do CT scans distinguish between and how does this happen

Answer 16

Different types of soft tissue as well as between bone (or teeth) and soft tissue. This is because X rays are absorbed more by bones and teeth than by soft tissue

Question 17

What is the frequency range of the normal human ear

Answer 17

From about 20Hz to 20,000Hz

Question 18

What are sound waves

Answer 18

Sound waves are longitudinal waves and cause vibrations in a medium, which are detected as sound. They can be reflected (echoes) and diffracted

Question 19

What are echoes caused by

Answer 19

Echoes are caused by sound waves reflected from a smooth, hard surface

Question 20

The pitch of a note increases if the ………… Increases

Answer 20

The pitch of a note increases of the frequency of the sound waves increases

Question 21

What increases the loudness of a sound

Answer 21

Increasing the amplitude of the sound wave

Question 22

What produces sound waves

Answer 22

Vibrations created in a musical instrument when it is played produce sound waves

Question 23

What is ultrasound

Answer 23

Ultrasound is acoustic (sound) energy, in the form of waves with a frequency above the human hearing range (20,000Hz)

Question 24

What are ultrasound waves used for in medicine

Answer 24

Pre-natal scanning and the removal of kidney stones

Question 25

What happens when ultrasound waves meet a boundary between two different media

Answer 25

Ultrasound waves are partially reflected when they meet a boundary between two different media

Question 26

Why is an ultrasound scan safer than an x Ray

Answer 26

An ultrasound scan is non ionising, so it is safer than an X-ray

Question 27

What type of wave has the smallest wavelength

Answer 27

Gamma rays

Question 28

What types of waves can be used for communication

Answer 28

Radio waves, microwaves, infrared and visible light

Question 29

Whats the hazard of exposure to microwaves

Answer 29

Heating of body tissue

Question 30

What is a use of visible light

Answer 30

Photography

Question 31

What is a use of ultraviolet

Answer 31

Security marking

Question 32

What is the hazard of exposure to X rays

Answer 32

High doses kill cells

Question 33

What can exposure to gamma rays cause

Answer 33

Genetic mutations

Question 34

Characteristics of X rays

Answer 34

They have a very short wavelength, high energy and cause ionisation

Question 35

What do properties of X rays include

Answer 35

-They affect a photographic film in the same way as light -They are absorbed by metal and bone -They are transmitted by soft tissue

Question 36

What are the problems with the use of high energy ionising radiation, and what precautions therefore need to be taken

Answer 36

The use of high energy ionising radiation can be dangerous, and precautions need to be taken to monitor and minimise the levels of radiation that people who work with it are exposed to

Question 37

How can you use ultrasound to determine how far away a boundary is

Answer 37

Ultrasound waves are partially reflected when they meet a boundary between two different media. They time taken for the reflections to reach a detector can be used to determine how far away such a boundary is (distance = [wave] speed x time)

Question 38

What is the pitch of a sound determined by

Answer 38

Its frequency

Question 39

What is the loudness of a sound determined by

Answer 39

Its amplitude

Question 40

What can be used to produce ultrasound waves

Answer 40

Electronic systems