Introduction to Refraction:

• Refraction is the bending of light as it passes from one medium to another.

• It occurs due to the change in the speed of light when it moves from one medium to another.

Prisms and Refraction:

• A prism is a transparent optical element with flat, polished surfaces that can refract light.
• When light enters a prism, it slows down and bends (refracts) towards the normal line.

Dispersion of Light:

• Prisms also cause dispersion, which is the separation of white light into its constituent colors.

• This happens because different colors of light have different wavelengths and are bent by different amounts when passing through the prism.

Prism Terminology:

• Base: The wider, flat surface of the prism.
• Apex: The pointed end of the prism.
• Angle of Deviation: The angle by which the light is bent inside the prism.
• Angle of Incidence: The angle at which light enters the prism.
• Angle of Emergence: The angle at which light exits the prism.

Rainbow Formation:

• Rainbows are natural examples of light dispersion and refraction.

• Raindrops act like tiny prisms, dispersing sunlight into its spectrum of colors.

Practical Applications:

• Prisms are used in various optical instruments, such as binoculars, spectrometers, and camera lenses.

• They are also used in physics experiments to study the properties of light.

Total Internal Reflection:

• Total internal reflection occurs when light cannot exit a medium and is reflected back inside.

• This phenomenon is used in optical fibers for communication.

Critical Angle:

• The critical angle is the angle of incidence beyond which total internal reflection occurs.

• It depends on the refractive indices of the two media.

Colors of the Spectrum:

• The visible spectrum consists of seven primary colors: red, orange, yellow, green, blue, indigo, and violet (ROYGBIV).
• These colors are seen when white light is dispersed through a prism.

Let’s practice!