14 electromagnetic spectrum

Question 1

Definition

Electromagnetic Spectrum

Answer 1

Transverse waves that travel with the same speed in vacuum which is the speed of light in vacuum, 3.0x10⁸.

Question 2

Components

Electromagnetic Spectrum

Answer 2

1. Radiowaves
2. Microwaves
3. Infra-red Radiation
4. Visible Light
5. Ultraviolet
6. X-rays
7. Gamma Rays

7-1: increasing wavelength

1-7: Increasing frequency

Question 3

Properties

Electromagnetic Spectrum

Answer 3

• Transfer energy from one place to another
• Transverse waves
• Can travel through vacuum with the speed of light, 3.0 x 10⁸
• Show wave properties like reflection and refraction
• Obey wave equation, v = fλ

Question 4

Uses

Radiowaves

Answer 4

• Amplitude modulation (AM) radio communication
  
  • Long wave (LW)
  • Medium wave (MW)
  • Short wave (SW)
• High-quality frequency modulation (FM) radio communication and terrestrial television communication
  
  • Very high frequency (VHF)
• Terrestrial television communication
  
  • Ultra high frequency (UHF)

Question 5

Uses

Microwaves

Answer 5

• Microwave ovens
• Television signals
• Satellite communication and mobile phone networks

Question 6

Uses

Infra-red Radiation

Answer 6

• Search-and-rescue
• Surveillance cameras
• Medical diagnoses
  
  • Thermal imaging equipment
• Remote controls
  
  • Light emitting diodes (LEDs)

Question 7

Uses

Visible Light

Answer 7

• Weld metals together
• Cut through hard materials such as steel
• Cut hundreds of layers of cloth with the same pattern simultaneously
• ‘Spot weld’ detached retina
• Cauterising of blood vessels
  
  • Light Amplification by Stimulated Emission of Radiation (LASER)

Question 8

Uses

Ultraviolet Radiation

Answer 8

• Sterilisation
• Forgery detection
• Fluorescent lamps
• Sunbeds

Question 9

Uses

X-rays

Answer 9

• Diagnostic tool in medicine and dentistry
• Airport security
• Cancer treatment
• Checking of welds
• Crystal analysis in paints

Question 10

Uses

Gamma Rays

Answer 10

• Sterilisation
• Cancer treatment
• Checking of welds

Question 11

Definition

Ionisation

Answer 11

The process where an electron is given enough energy to break away from an atom.

Question 12

Effects

Ionisation

Answer 12

Two charged particles are formed due to ionisation. This can result in destruction and/or modification of living cells. Hence, diseases such as cancer can develop.

Question 13

Properties

Electromagnetic Spectrum

Answer 13

1. They transfer energy from one place to another.
2. They are transverse waves.
3. They can travel through vacuum.
4. They travel through vacuum with the speed of light.
5. They all show wave properties like reflection and refraction.
6. They obey the wave equation, v = fλ