Irradiance and Distance

Introduction

• Irradiance is the power per unit area when radiation hits a surface.
• When we talk about how irradiance changes with distance from a point source of radiation, we observe a specific relationship.

Inverse Square Law

• Irradiance and distance follow an inverse square law relationship.
• This means that as you move farther away from a point source of radiation, the irradiance decreases.

Mathematical Representation

• The relationship can be expressed as:
• $E_1 \times r_1^2 = E_2 \times r_2^2$
  • $E_1$ represents the irradiance at distance $r_1$ from the source.
  • $E_2$ represents the irradiance at distance $r_2$ from the source.
  • The product of irradiance and the square of the distance is constant.

Application

• This principle is essential in various fields, including physics, astronomy, and photography.
• It helps understand how the intensity of radiation or light decreases as you move away from a source.

Summary

• Irradiance and distance from a point source of radiation follow an inverse square law relationship.
• The product of irradiance and the square of the distance is constant.
• This principle is widely used in physics, astronomy, and photography to understand how radiation or light intensity changes with distance.