Optical fibre is based on which of the following principles? a. Principle of reflection of light b. Principle of refraction of light c. Principle of total internal reflection d. Principle of dispersion of light

Optical fibre is based on which of the following principles? a. Principle of reflection of light b. Principle of refraction of light c. Principle of total internal reflection d. Principle of dispersion of light Correct Answer Only c

The correct answer is the Only c.

Key Points

• Optical fibre
  • When the light ray enters the optical fibre, it undergoes total internal reflection as the angle formed by the ray is greater than the critical angle.
  • Hence the only c is the correct option.
• Total Internal reflection
  • Total internal reflection is a complete reflection of a ray of light within the same medium such as water or glass.
  • The phenomenon occurs if the angle of incidence is greater than a certain limiting angle, called the critical angle
  • If the light is moving from a denser medium (water) to lighter medium(air) and the angle of incidence (i) is greater than the critical angle (c) that is i>c, then light undergoes the phenomenon called the total internal reflection.

Important Points

• Refraction of light
  • Bending of light away from normal while moving from one medium to another.
  • For example, a view of a broken pencil or coin inserted in a beaker of water.
• Reflection of light
  • Incident ray gets reflected from the polished surface having the angle of incidence equal to the angle of reflection.
• Dispersion of light
  • This process of white light splitting into its constituent colours is termed dispersion.
  • For example when light passes from prism then it splits into its spectrum of colours (in order violet, indigo, blue, green, yellow, orange, and red called VIBGYOR).

 Additional Information

• Optical fibres are used in the communication devices to send and receive data.
• Benefits of optical fibre cable
  • The data security is excellent.
  • It is cost-effective.
  • It won’t be affected by interference.
  • Less signal degradation.
  • Thin and non-flammable.
  • Economical and cost-effective.
  • Less power consumption.
  • Optical fibres are also used in endoscopy.