The Electromagnetic Spectrum

Question 1

What are the EM waves?

Answer 1

Radio-waves, Microwaves, Infra-red, Visible light, UltraViolet, X-rays, Gamma rays

Question 2

What are the similarities of EM waves?

Answer 2

All transverse waves
Travel at the same speed through a vacuum

Question 3

Unit for angles

Answer 3

Degree (°)

Question 4

Unit for frequency

Answer 4

Hertz (Hz)

Question 5

Unit for length

Answer 5

Metre (m)

Question 6

Unit for speed/velocity

Answer 6

Metre/second (m/s)

Question 7

Unit for time

Answer 7

Second (s)

Question 8

Order EM waves from longest to shortest wavelength:

Answer 8

Radio-waves, Micro-waves, Infra-red, Visible Light, UltraViolet, X-Rays, Gamma Rays

Question 9

Order EM waves from low to high frequency:

Answer 9

Radio-waves, Microwaves, Infra-red, Visible Light, UltraViolet, X-Rays, Gamma Rays

Question 10

What are the order of colours in visible light?

Answer 10

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Question 11

What colour has the longest wavelength and the lowest frequency?

Answer 11

Red

Question 12

What colour has the shortest wavelength and the highest frequency?

Answer 12

Violet

Question 13

What are the uses of radio waves?

Answer 13

Broadcasting and communications

Question 14

How does long-wave radio transmit?

Answer 14

Long-wave radio bends around the earth so they transmit over long distances (1km

Question 15

How does short-wave radio transmit?

Answer 15

It reflects from the ionosphere (part of the atmosphere) so they can be received at long distances (100m)

Question 16

What is the wave length of TV and FM radio waves?

Answer 16

Shortwave lengths (1m), need to be in direct sight of transmitter

Question 17

What are the uses of microwaves?

Answer 17

Cooking and satellite transmissions

Question 18

How does satellite transmission work?

Answer 18

Signal is transmitted from earth to orbit, satellite transmits signal to a satellite dish on earth

Question 19

How are microwaves used for cooking?

Answer 19

Microwaves are absorbed by water molecules in food, it penetrates the food before being absorbed and conducted/ convected

Question 20

What are the uses of Infra-red?

Answer 20

Heaters and night vision equipment

Question 21

Is infrared given out by all objects?

Answer 21

IR is given out by all objects, the hotter the object the more IR given out

Question 22

How does night vision equipment work?

Answer 22

IR is detected using the equipment which is turned into an electrical signal which can be displayed on screen

Question 23

What are the uses of visible light?

Answer 23

Optical fibres and photography

Question 24

How does optical fibres work?

Answer 24

Waves are bounced off the sides of a very narrow core
A pulse of light enters the fibre at a certain angle and reflects again and again until it emerges at the other end

Question 25

What are the uses of Ultra Violet?

Answer 25

Fluorescent lamps

Question 26

How do fluorescent lamps work?

Answer 26

UV light is absorbed by a chemical which emits visible light

Question 27

What are the uses of X-Rays?

Answer 27

Observing the internal structure of objects and materials (medical applications)

Question 28

What are the uses of Gamma rays?

Answer 28

Sterilising food and medical equipment

Question 29

How does Gamma rays sterilise food?

Answer 29

It kills microbes - keeps food fresh for longer

Question 30

How does Gamma rays sterilise medical equipment?

Answer 30

It kills all the microbes (better than boiling plastic instruments which may be damaged from high temperatures)

Question 31

Which EM spectrum waves are dangerous?

Answer 31

Microwaves, Infrared, Ultraviolet, Gamma rays

Question 32

What types of waves are usually more dangerous?

Answer 32

Waves with higher frequencies (they have more energy)

Question 33

What damage can microwaves cause?

Answer 33

Internal heating of body tissue

Question 34

How can you protect yourself against microwaves?

Answer 34

Microwave ovens have shielding to stop microwaves escaping

Question 35

What damage can infrared cause?

Answer 35

It can cause skin burns

Question 36

How can you protect yourself against microwaves?

Answer 36

Using insulating materials like oven gloves

Question 37

What damage can ultraviolet cause?

Answer 37

It can cause skin cancer and blindness

Question 38

How can you protect yourself against ultraviolet?

Answer 38

Avoid exposure to the sun and wear suncream

Question 39

What damage can Gamma rays?

Answer 39

It can cause mutations and cancer

Question 40

How can you protect yourself against gamma rays?

Answer 40

Store radioactive material in lead lined boxes