# Formula Destructive Interference Condition Path difference    Integer    Wavelength

## Path difference

Unit
The path difference of two waves, which travel to the observation point (e.g. to the point where a bright interference fringe can be seen). The path difference thus indicates by how many wavelengths a wave leads or lags another wave.

For destructive interference, the path difference takes the following values:$\Delta s ~=~ \frac{1}{2} \, \lambda,~ \frac{3}{2} \, \lambda,~ \frac{5}{2} \, \lambda, ~...$

## Integer

Unit
Integer multiple of the wavelength takes the following values in the case of destructive interference: $$m = 1, 2, ...$$. This integer indicates the factor by how much one wave precedes the other.

## Wavelength

Unit
Wavelength of the two waves under consideration. So the wavelength of the light used.