Question

Create a poster of the electromagnetic spectrum. Identify the different waves and draw illustrations or paste pictures showing their wavelength. Include images of uses of each wave in the spectrum. Find out and write interesting features of each wave in the poster.

Answer 1

THE ELECTROMAGNETIC SPECTRUM
Electromagnetic waves are forms of energy that travel at the speed of light (3 × 108 m/s) in vacuum.
They differ in wavelength (the distance between two waves) and frequency.
Wave	Wavelength (Approx.)	Examples	Uses	Interseting Features
1. Radio Waves	103 m to 10-1 m (Longest)	Radio tower Radio	Radio and TV broadcasting Communication (Walkie-talkie) Navigation (ships and aircraft) Amateur radio	Longest wavelength, lowest energy Can travel long distances Can bend around obstacles
2. Microwaves	10⁻1 m to 10-3 m	Microwave oven Wi-Fi	Cooking food Wi-Fi and mobile communication Satellite communication Radar systems	Used in ovens to make water molecules Cannot pass through metal
3. Infrared Waves	10-3 m to 10-6 m	Remote control Thermal camera	Remote controls Thermal imaging Heat lamps Night vision cameras	We felt it as heat Emitted by all warm objects Used in thermal cameras to see heat, not light
4. Visible Light	700 nm to 400 nm (10-7 m)	Rainbow Human eye	Vision Photography Lighting Plants use it for Photosynthesis	Only part visible to humans Contains VIBGYOR colours
5. Ultraviolet Rays	10-7 m to 10-8 m	UV lamp Sunscreen	Sterilising equipment Detecting fake currency Tanning Helps the body produce Vitamin D	Higher energy than visible light Can cause sunburn Kills many germs
6. X-Rays	10-8 m to 10-11 m	Chest X-ray	Medical X-rays Airport baggage scanners Inspecting internal structures	Pass through soft tissues but not bones Excess exposure is harmful
7. Gamma Rays	Less than 10-11 m (Shortest)	Atomic nucleus	Cancer treatment (Radiotherapy) Sterilising medical equipment Space research	Highest energy Shortest wavelength Produced in nuclear reactions
Longer Wavelength → Lower Energy ⟶ Shorter Wavelength → Higher Energy