Refractive Index

Refractive Index

Introduction

• The speed of light varies depending on the medium it travels through.
• When light passes from one medium to another, it changes speed and direction. This phenomenon is called refraction.

Speed of Light

• Light travels at its maximum speed in a vacuum, which is approximately 3 × 10^8 meters per second (m/s).
• In other materials, such as air or glass, light travels at different speeds, which are slower than its speed in a vacuum.

Frequency of Light

• The frequency of light, which determines its colour, remains constant as it refracts from one medium to another.
• Refraction affects the speed and direction of light but not its frequency.

Refractive Index

• The refractive index (n) of a material quantifies how much the speed of light changes when it enters that material from a vacuum (or air, which is approximately the same).
• It is calculated using the equation:
• n = c / v
• Where:
  • n is the refractive index of the material.
  • c is the speed of light in a vacuum (approximately 3 × 10^8 m/s).
  • v is the speed of light in the material.

Interpretation

• The refractive index is a measure of how much slower light travels in a particular material compared to its speed in a vacuum.
• A higher refractive index indicates slower light propagation in the material.

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Refractive Index

Example Calculation

Summary