propagation and velocity of light

Define Optics

the science of light

Define Geometrical optics

the understanding of the basics of light

Give examples of geometrical optics

reflection , refraction , mirrors, prisms and lenses

Define Physical optics

the understanding of the phenomena of light waves

Give examples of physical optics

interference, diffraction, polarization

What is geometrical optics also known as

ray optics

What is physical optics also known as

wave optics

Define a point source

a light source which is very small

Define an extended light source

several point sources or those of appreciable size

Define rectilinear propagation

the property of light to travel in a straight line as a wave

What was Sir Isaac Newtons theory of light

that light is made up of tiny particles

What principle proposes light is made up of waves

Huygens Principle

HP : Define optical medium

any space which light travels through

HP: Define an isotropic medium

an optical medium which has the same properties in all directions

HP : Define a homogenous medium

an optical medium that has the same properties throughout its mass

Define wavelength

the distance between successive points of similar phase

what is the unit for wavelength for light

nanometres

Define frequency

the number of complete waves produced in one second

what is the unit for frequency

Hz

Define amplitude

the peak valve of the wave which is a measure of height of the wave crest or depth of the wave trough

Define velocity

the rate at which the wave travels

What are the units for velocity

metres per second (ms-1)

What is the Velocity of light in vaccum

3 x 108 ms-1

What is the formula for velocity

Velocity of light = frequency x wavelength
v = ν λ

what is a a pencil of rays

a group of rays

What is the central ray in each pencil ray called

chief ray

what is this type of ray

A divergent pencil of rays

What is this type of ray called

A convergent pencil of rays

What is this type of ray called

A parallel pencil of rays

Define vergence

the reciprocal of the distance from the point to
the source or focus

curvature of the wave front

what is the vergence equation

vergence = 1/ length

what symbol is also used for vergence

L’ ( L dash)

when is the length positive in vergence calculations

when the distance from the point to the focus point is in the same direction as the light rays

when is the length negative in vergence calculations

when the distance from the point to the focus point is in the opposite direction as the light rays