Question

An optical device ‘X’ is placed obliquely in the path of a narrow parallel beam of light. If the emergent beam gets displaced laterally, the device ‘X’ is ______.

Options

• plane mirror

• convex mirror

• glass slab

• glass prism

Answer 1

An optical device ‘X’ is placed obliquely in the path of a narrow parallel beam of light. If the emergent beam gets displaced laterally, the device ‘X’ is glass slab.

Explanation:

In a glass slab, a parallel light beam refracts at the air-glass and glass-air interfaces. As it moves laterally, the emergent beam stays parallel to the incident beam. The thickness, angle of incidence, and refractive index of the slabs all affect this displacement.