TransverseTransverseLongitudinalLongitudinal

WaveWave

TransverseTransverseLongitudinalLongitudinal

Eg. SoundEg. Sound Eg. LightEg. Light

A component of Electromagnetic Spectrum

A component of Electromagnetic Spectrum

Electromagnetic Spectrum

• Light is just a component of the Electromagnetic (EM) Spectrum

• There are altogether 7 components in the spectrum

7 main components in the EM spectrum

Gamma-ray

X-rayUltra-violet

Infra-red

Micro wave

Radio wave

Violet Blue Green

Yellow

Orange

RedIndigo

Gamma-ray

X-ray Ultra-violet

Infra-red

Micro wave

Radio wave

Wavelength

LongerShorter

Frequency

LowerHigherFrequency =

no. of complete wave in 1s

Wavelength

Gamma-ray

X-ray Ultra-violet

Infra-red

Micro wave

Radio wave

Shortest to Longest wavelength

1. Gamma-ray

2. X-ray

3. Ultraviolet

4. Visible Light

5. Infrared

6. Microwave

7. Radio wave

Properties

• EM waves are all transverse wave

• The speed of all the EM wave in vacuum is the same

• How fast is the speed of light in vacuum?– Speed of Light = 3 x 108 m/s– Speed of all the EM wave = 3 x 108 m/s

Properties & Application Name Properties Application

Gamma-ray Penetrate matter Kill cancer cells

X-ray Less penetrating than Gamma-ray

Take “pictures” of bones in the body

Ultraviolet Given off by the Sun in large quantities

Detect counterfeit notes

Visible Light The only EM waves visible to our eyes

Enables us to see things

Infrared Produced by all objects with temperature higher than 0 Kelvin (-273oc)

Heating

Microwave Generated by extremely high frequency electric current

Cooking in microwave

Radio wave Generated by high frequency electric current

TV & radio broadcasting

UltravioletUltraviolet

X-RayX-Ray

Gamma RayGamma Ray

InfraredInfrared

Visible LightVisible Light

MicrowaveMicrowave

Radio waveRadio wave

ConclusionConclusion

Waves in EM Spectrum are all transverse waves.

They travel at the same speed, 3 x 108 m/s, in vacuum

Gamma-ray

X-ray Ultra-violet

Infra-red

Micro wave

Radio wave