Electromagnetic Spectrum

Question 1

What is the electromagnetic spectrum?

Answer 1

• A continuous spectrum of tranverse waves which light is a part of
• Electromagnetic waves transfer energy and can transfer information, and all travel at the same speed (speed of light) through a vacuum

Question 2

What are the 7 types of electromagnetic waves in order of decreasing wavelength and range, and increasing frequency and energy?

Answer 2

• Radio
• Microwave
• Infrared
• Visible light
• Ultraviolet
• X-rays
• Gamma rays

Question 3

What is the effect on wavelength and frequency as you move down the electromagnetic spectrum?

Answer 3

• Wavelength goes from highest to lowest (radio with the highest, gamma with the lowest
• Frequency goes from lowest to highest (radio with the lowest, gamma with the highest

Question 4

What is the effect on energy and range as you move down the electromagnetic spectrum

Answer 4

• Range goes from highest to lowest (radio with the highest, gamma with the lowest
• Energy goes from lowest to highest (radio with the lowest, gamma with the highest) - meaning the highest energy within the radiation emitted

Question 5

What is the order of colours in the visible light spectrum in terms of decreasing wavelength and range, and increasing frequency and energy?

Answer 5

• Red
• Orange
• Yellow
• Green
• Blue
• Indigo
• Violet

(Roy G Biv)

Question 6

What are the main uses of radio waves?

Answer 6

Communications and broadcasting, like radios and TVs

Question 7

What are the main uses of microwaves?

Answer 7

• Heating food
• Communications like satellite transmissions, wifi and cellular data

Question 8

What are the main uses of infrared waves?

Answer 8

• Thermal imaging for infrared cameras, night vision and medical scans
• Heaters
• Remote controls

Question 9

What are the main uses of visible light?

Answer 9

• Seeing things and taking photographs/videos
• Fibre-optic communications

Question 10

What are the main uses of ultraviolet waves?

Answer 10

• Fluroescent bulbs (energy efficient)
• Invisible ink (security marking)
• Sun-tanning

Question 11

What are the main uses of x-rays?

Answer 11

Observing the internal structure of objects, used in medicine, security and industry

Question 12

What are the main uses of gamma-rays?

Answer 12

• Sterilising food and medical equipment
• Treating cancer (radiotherapy)

Question 13

What are the dangers of radio waves?

Answer 13

There are no dangers

It is not dangerous due to its very low frequency and energy. As you go down the spectrum the danger increases

Question 14

What are the dangers of microwaves?

Answer 14

Internal heating of bodily tissues

Question 15

What are the dangers of infrared waves?

Answer 15

Skin burns

Question 16

What are the dangers of visible light?

Answer 16

Eye damage

Question 17

What are the dangers of ultraviolet waves?

Answer 17

• Eye damage (blindness)
• Damage to skin cells (sunburn) and eventually skin cancer

Ultraviolet, x-rays and gamma rays are all ionising, so have the ability to cause cancer

Question 18

What are the dangers of x-rays?

Answer 18

• Kills + damages cells, causing mutations
• Cancer

Question 19

What are the dangers of gamma-rays?

Answer 19

• Kills + damages cells, causing mutations
• Cancer

Question 20

What are some preventative measures you can take to protect yourself from damaging electromagnetic waves?

Answer 20

• Limiting exposure (decreasing time, increasing distance)
• Shielding the source, and wearing dense, absorbing equiment, or wearing sunscreen in the case of ultraviolet
• Eye protection can protect against infrared, visible light and ultraviolet