Properties of Light Waves

Characteristics of Light

10 facts about light

Light interacts with matter by:TransmissionAbsorption Scattering

Components of the E.S. Radio Waves Microwaves Infrared Waves Visible Light Ultraviolet waves X-rays Gamma rays

Particles Waves Combination of Both

Definition:Light is a wave composed of

oscillating electric and magnetic fields

• Fields are perpendicular to the direction in which the wave moves

• Transverse Waves

Electromagnetic waves consist of electric and magnetic fields.

The fields are mutually perpendicular.

Electromagnetic (EM) Waves

• Electric and magnetic fields are at right angles to each other

Click below to watch the Visual Concept.

Visual Concept

• All electromagnetic waves move at the speed of light

• 2.99 X 108 m/s• use 3.00 X 108 m/s for problems

• Relationships between frequency, wavelength, and speed are the same as sound

c = f λ

• What is the λ range for the FM radio band?

3.4 – 2.78 m

• What is the frequency of an electromagnetic wave if it has a wavelength of 1.0 km?

3.0 x 105 Hz

• Shortwave radio is broadcast between 3.5 and 29.7 Hz. To what range of wavelengths does this correspond? Why is it called shortwave?

85.7 to 10.1 m

• What is the frequency of highly energetic ultraviolet radiation that has a wavelength of 125nm?

2.4 x 1015 Hz

• Brightness is proportional to the source of the light

• Brightness = 1/distance 2

Illumination is measured in lumens (lm).Illumination depends on the brightness of the source and the distance from the source.

Predict the relationship between illumination and distance.It is an inverse square relationship.