Question

• Describe electromagnetic waves, frequency of light, wavelength of light, and speed of light in vacuum and in medium.
• In your own words, explain index of refraction and light propagation from one medium to another.
• In your own words, explain polarization and light intensity.

Answer 1

Electromagnetic waves are the waves that are created as a result of vibrations between between electric and magnetic field.

Frequency describes the number of waves that passes a fixed place in a given amount of time. Usually frequency is measured in hertz(Hz).

Wavelength equals distance between two successive wave crests or trough. Measured in nanometer.

Speed of light in vacuum is  

Index of refraction =

where c is velocity of light in vacuum

and v is the speed of light in medium

When light propagates from one medium to another, speed changes, wavelength changes but frequency remains constant.

Polarization is a property applying to transverse wave that specifies the geometrical orientation of the oscillations. In a transverse wave the direction of the oscillation is perpendicular to the direction of the motion of the wave.

Light Intensity refers to the strength or amount of light produced by a specific lamp source. It is the measure of the wavelength - weighted power emitted by a light source.