EMS 1

Question 1

Define the Electromagnetic spectrum.

Answer 1

The electromagnetic (EM) spectrum is the range of all types of EM radiation.
It covers a frequency range, from 1 hertz (Hz) to 1025 hertz.

Question 2

Identify and describe the division within the electromagnetic spectrum.

Answer 2

Radio waves, Infrared, Visible Spectrum, Ultraviolet, X-rays and Gamma Rays

Question 3

Describe the electromagnetic spectrum and application to different
frequency bands. (A to F)

Answer 3

A 0 to 250 MHz Over The Horizon (OTH) Radar
B 250 to 500 MHz
C 500 to 1000 MHz Ground Penetration Radar
D 1000 to 2000 MHz 1- 2 Ghz Long Range Air Surv / GPS
E 2000 to 3000 MHz 2-3 GHz ATC – Airport
F 3000 to 4000 MHz 3-4 GHz 5G (Mid) Band

Question 4

Demonstrate knowledge of the practical assessment of Radio Waves

Answer 4

Lowest FRQ in the EM Spectrum and the longest wavelength.
* Energy : Very low energy.
* Applications : Radio and TV communications.
* Range : Can travel great distances, as they are reflected off the Ionosphere.

Question 5

Demonstrate knowledge of the practical assessment of Microwaves

Answer 5

• “Micro” – small, having shorter wavelengths.
• Energy : Low energy
• Applications : Heating up food, Mobile Phones
• Range : Can travel large distances but penetrate the atmosphere. Line-of-sight.

Question 6

Demonstrate knowledge of the practical assessment of Infrared

Answer 6

• Sensed as heat. Can be seen by animals.
• Energy : Moderate energy
• Applications : Heating, Television remotes
• Range : Medium range
• Subdivisions : NIR, SWIR, MWIR, LWIR, FIR

Question 7

Demonstrate knowledge of the practical assessment of Visible Light

Answer 7

• Comprised of 7 colours : ROYGBIV
• Can be perceived by the human eye.
• Energy : Photon dependant.
• Applications : Optics.
• Range : Medium range.

Question 8

Demonstrate knowledge of the practical assessment of Ultraviolet

Answer 8

• UV is a higher FRQ wave.
• UV radiation is present in sunlight.
• Energy : UV photons have greater energy than visible light.
• Applications : Security tags, invisible ink.
• Range : Medium range.
• Exposure : Effects of sun tan and sun burn.

Question 9

Demonstrate knowledge of the practical assessment of X-Ray’s

Answer 9

• High FRQ in the EM Spectrum and a very short wavelength.
• Energy : High energy
• Applications : X-Ray imaging.
• Range : Short range
• Exposure : Hazardous to health – burns and radiation sickness.

Question 10

Demonstrate knowledge of the practical assessment of Gamma Rays

Answer 10

• Highest FRQ in the EM Spectrum and the shortest wavelength.
• Energy : Very High energy.
• Applications : Radiotherapy, medical imaging.
• Range : Short range.
• Exposure : Hazardous to health – Cancer.

Question 11

Describe the electromagnetic spectrum and application to different
frequency bands. (G to M)

Answer 11

G 4000 to 6000 MHz 4-6 GHz Weather Radars
H 6000 to 8000 MHz 6-8 GHz Wi-Fi 6E
I 8000 to 10000 MHz 8-10 GHz Synthetic Aperture Radar
J 10000 to 20000 MHz 10-20 GHz Satellite Communications
K 20000 to 40000 MHz 20-40 GHz Satellite Communications
L 40000 to 60000 MHz 40-60 GHz Astronomy
M 60000 to 100000 MHz 60-100 GHz Automotive Radar