The Electromagnetic Spectrum

Question 1

https://www.thinglink.com/scene/786642971607957505

Answer 1

https://en.wikipedia.org/wiki/Wave_height

Question 2

wavelenght?

Answer 2

wavelength is the length of a wave, it is measure from 1 point on a wave to an identical point on the next wave

Question 3

amplitude?

Answer 3

amplitude is the height of a wave, it is measure from the midpoint to the peak/trough

Question 4

Frequency?

Answer 4

Frequency is the number of waves that pass a fixed point every second: measured in Hertz (Hz)

Question 5

Time Period?

Answer 5

Time taken for a full wave to pass a point: measured in seconds

Question 6

Time period (S) = ?

Answer 6

Time period (S) = 1 / frequency (Hz)

Question 7

What are the two kinds of waves?

Answer 7

1. Transverse

2. Longitudinal

Question 8

For waves travelling at the same speed, shorter wavelength = ?

Answer 8

Higher frequency

Question 9

Wavelength and frequency are?

Answer 9

Inversely proportional

Question 10

wave speed =?

Answer 10

frequency (Hz) * wavelength (M)

Question 11

What are the waves in the EM spectrum (longest to shortest wavelength)?

Answer 11

1. Radio waves
2. Micro waves
3. Infrared Radiation
4. Visible Light
5. Ultraviolet
6. X-Rays
7. Gamma Rays

Question 12

What speed do all EM waves travel at?

Answer 12

The speed of light - in a vacuum is 300 mil m/s

Question 13

What kind of waves are EM waves?

Answer 13

Transverse

Question 14

What are radio waves used for mainly?

Answer 14

communications - tv and radio

Question 15

What do radio waves, microwaves, infrared radiation and visible light all have in common?

Answer 15

They have the longest wavelengths

Question 16

Why are waves with longer wavelengths used for communications?

Answer 16

1. They can travel further

2. They’re not dangerous

Question 17

What are microwaves used for?

Answer 17

1. satellite communications - including Sat TV
2. mobile phones
3. Microwave ovens - these heat up food faster than ordinary ovens because microwaves can penetrate food and are absorbed by water molecules in food - heating it up.

Question 18

What is infrared radiation used for?

Answer 18

1. to send tv remote signals
2. night vision and heat sensing cameras
3. can be used in optical fibres - normally however visible light is used

Question 19

What is visible light used for?

Answer 19

1. our eyes can see visible light, so any methods of visible communication relies on visible light
2. tv
3. photography
4. optic fibres (broadband)

Question 20

Light from the sun (or ordinary lamps) is called?

Answer 20

white light because it has all the colours of the visible light spectrum in it

Question 21

as the wavelength shortens…

Answer 21

the wave becomes more dangerous

Question 22

What is ionising radiation?

Answer 22

waves with short wavelengths have enough energy to knock electrons off the outer shells of atoms, damaging the cell the atom is apart of, and even making the cell cancerous

Question 23

Ultraviolet wave uses?

Answer 23

1. To detect forgeries at banks
2. tan beds
3. bee’s use UV rays to detect pollen

Question 24

How many types of UV rays are there?

Answer 24

ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC)

Question 25

UVC?

Answer 25

UVC rays can't pass through the ozone layer therefore only harmful in space

Question 26

UVB?

Answer 26

Affects top layer of skin, makes you tanned, red, burnt, can cause cancer

Question 27

UVA?

Answer 27

UVA is actually more dangerous than UVB because although UVB has a shorter wavelength, it is the perfect wavelength to be absorbed by the top layer of skin and therefore UVA penetrates deeper. DNA damage + skin aging

Question 28

Uses of X-Rays?

Answer 28

1. medical imagery | 2. metal detectors

Question 29

How do medical professionals who use x-rays protect themselves?

Answer 29

1. They leave the room 2. They wear lead aprons 3. They go behind screens 4. Limit exposure time

Question 30

Uses of gamma rays?

Answer 30

1. Radiotherapy | 2. Sterilize medical equipment

Question 31

Gamma knife?

Answer 31

Targeted gamma rays that can destroy tumours

Question 32

How are radio waves produced?

Answer 32

Oscillations in electrical circuits

Question 33

How are microwaves produced?

Answer 33

Produced in microwaves and other transmitters

Question 34

How is infrared radiation produced

Answer 34

Radiated from any object with a temperature

Question 35

How is visible light produced?

Answer 35

Comes from the sun

Question 36

How is ultraviolet radiation produced

Answer 36

High temperature surfaces such as the sun produce it

Question 37

How are x-rays produced?

Answer 37

By accelerating electrons through a potential diffference

Question 38

How are gamma rays produced?

Answer 38

By nucleus changes of an atom