Question

For refraction through a plane glass slab, dimension $d$ is called

• A. refraction shift
• B. lateral shift
• C. emergence shift
• D. incidence shift

Answer 1

Answer: (B)

For a rectangular slab, refraction takes place at two interfaces (air-glass and glass-air).
It is easily seen from diagram that $r_2=i_1$,
i.e., the emergent ray is parallel to the incident ray $-$ there is no deviation,
but it undergoes a lateral shift.