To determine the angle of the given prism.
Spectrometer, prism, magnifying glass, sodium vapor lamp.
When a beam of light strikes on the surface of transparent material (Glass, water, quartz crystal etc.), a portion of the light is transmitted and the other portion is reflected. When a beam of light strikes on a plane surface, the angle of reflection will be the same as angle of incidence.
Fig (2) Fig (3)
If the angle between two reflected ray is measured as θ, then the angle of the prism is