Radiation force on a surface is proportional to the intensity of light and the area of the surface. For a totally reflecting surface, the force is twice that on a totally absorbing surface for the same intensity and area.
Light of uniform intensity impinges perpendicularly on a totally reflecting surface. If the area of the surface is halved, the radiation force on it will become
Asked in UPSC NDA 2 2020 · Topic: Optics (Reflection and Refraction at plane and spherical surfaces)
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