Enter the Wien's displacement constant and the absolute temperature into the calculator to determine the peak wavelength of radiation. This calculator can also evaluate any of the variables given the others are known.

Wien's Displacement Law Formula

The following formula is used to calculate the peak wavelength of radiation emitted by a black body according to Wien's Displacement Law.

λ_max = b / T

Variables:

  • λ_max is the peak wavelength of radiation (meters)
  • b is Wien's displacement constant (2.8977729 x 10^-3 m.K)
  • T is the absolute temperature of the black body (Kelvin)

To calculate the peak wavelength of radiation, divide Wien's displacement constant by the absolute temperature of the black body. This will give the peak wavelength at which the black body emits radiation. As the temperature increases, the peak wavelength decreases, which is the principle of Wien's Displacement Law.

What is a Wien's Displacement Law?

Wien's Displacement Law is a principle in physics that states the wavelength of the peak radiation emitted by a black body is inversely proportional to its temperature. This means that as the temperature of a black body increases, the peak wavelength at which it emits radiation decreases. This law is used in various scientific fields, including astrophysics, to determine the temperature of stars and other celestial bodies based on the color of light they emit.

How to Calculate Wien's Displacement Law?

The following steps outline how to calculate Wien's Displacement Law:


  1. First, determine the value of the Wien's displacement constant (b) in meters. The value of b is 2.8977729 x 10^-3 m.K.
  2. Next, determine the absolute temperature of the black body (T) in Kelvin.
  3. Next, use the formula λ_max = b / T to calculate the peak wavelength of radiation (λ_max) in meters.
  4. Finally, calculate the Wien's Displacement Law.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Wien's displacement constant (b) = 2.8977729 x 10^-3 m.K

Absolute temperature of the black body (T) = 5000 K