Radiation (EM Spectrum)

Question 1

What speed do all waves in the electromagnetic spectrum travel at?

Answer 1

All waves in the electromagnetic spectrum travel at the speed of light - 3 x 10⁸ ms^-1.

Question 2

Give one application of radio waves.

Answer 2

• Broadcasting
• Satellite transmissions
• Communications

Question 3

What is meant by the wavelength of a wave?

Answer 3

Wavelength is the distance between a point on one wave and the same point on the next wave.

Question 4

Name the three quantities shown in this formula.

Answer 4

d = distance

v = speed

t = time

Question 5

Give one use of gamma rays.

Answer 5

• sterilising food and medical equipment
• treating cancer
• medical tracers

Question 6

Name the seven different types of waves in the electromagnetic spectrum.

Try to list them from long λ (wavelength) to short λ.

Answer 6

Radio (long λ)

Microwaves

Infrared

Visible

Ultraviolet

X-rays

Gamma rays (short λ)

Question 7

What is the unit for speed?

Answer 7

The unit for speed is metres per second (ms^-1)

Question 8

What is meant by the period of a wave?

Answer 8

The period of a wave is the time taken for one wave to pass.

Question 9

How is the frequency of a wave in the e.m. spectrum related to its energy?

Answer 9

The higher the frequency of a wave in the e.m. spectrum, the more energy the wave has.

Question 10

Give one use of visible light.

Answer 10

• photography
• illumination
  
  • car headlights
  • street lighting

Question 11

Give one application of microwaves.

Answer 11

• cooking
• mobile phone communications

Question 12

What is the unit for distance?

Answer 12

The unit for distance is metres (m)

Question 13

Name the three quantities shown in this formula.

Answer 13

v = speed

f = frequency

λ = wavelength

(the λ symbol is called ‘lambda’)

Question 14

What is the unit for time?

Answer 14

The unit for time is seconds (s)

Question 15

What is meant by the statement “A frequency of 16 Hz” ?

Answer 15

This means that there are 16 waves per second.

Question 16

What type of wave are microwaves an example of?

Answer 16

Microwaves are an example of transverse waves.

Question 17

Complete the following sentence:

All waves carry ……………

Answer 17

All waves carry energy.

Question 18

What type of wave is a sound wave an example of?

Answer 18

A sound wave is an example of a longitudinal wave.

Question 19

Which wave in the electromagnetic spectrum has the longest wavelength?

Answer 19

Radio waves have the longest wavelength.

Question 20

State one source of visible light.

Answer 20

Sources of visible light include:
* the Sun
* light bulbs
* anything hot enough to glow

Question 21

What is the unit for frequency?

Answer 21

The unit for frequency is hertz (Hz)

Question 22

State a detector of infrared radiation.

Answer 22

• photodiode
• phototransistor
• thermistor
• thermocouple

Question 23

Which wave in the electromagnetic spectrum has the greatest energy?

Answer 23

Gamma rays have the greatest energy.

Question 24

What is meant by the amplitude of a wave?

Answer 24

The amplitude of a wave is the height of the wave, measured from middle to top.

Question 25

Give one use of infrared.

Answer 25

• thermal imaging
• remote controls
• security systems

Question 26

What type of wave is a water wave an example of?

Answer 26

A water wave is an example of a transverse wave.

Question 27

From the diagram shown, identify the wavelength of the wave.

Answer 27

C is the wavelength.

Question 28

Give one use of X-rays.

Answer 28

• medical X-ray scans
• airport security scanners

Question 29

What is the unit for wavelength?

Answer 29

The unit for wavelength is metres (m).

Question 30

Which wave in the electromagnetic spectrum has the least energy?

Answer 30

Radio waves have the least energy.

Question 31

From the diagram shown, identify the amplitude of the wave.

Answer 31

D is the amplitude.

Question 32

Which wave in the electromagnetic spectrum has the shortest wavelength?

Answer 32

Gamma rays have the shortest wavelength.

Question 33

Give one use of ultraviolet.

Answer 33

• security marking
• detecting forged bank notes
• fluorescent lamps

Question 34

What is the unit for amplitude?

Answer 34

The unit for amplitude is metres, m.

Question 35

What do all waves in the electromagnetic spectrum have in common?

Answer 35

All waves in the electromagnetic spectrum travel at the same speed (the speed of light).

Question 36

Describe what is meant by gamma radiation.

Answer 36

• Gamma radiation is a wave in the electromagnetic spectrum
• Gamma rays have no mass or charge
• Gamma rays have a very short wavelength and a high frequency

Question 37

State a detector of radio waves.

Answer 37

An aerial is used to detect radio waves.

Question 38

What is meant by the frequency of a wave?

Answer 38

Frequency is the number of waves per second.

Question 39

What is the unit for period?

(period of a wave)

Answer 39

The unit for period is seconds (s).