Question

Explain refraction of light and lateral shift using a rectangular glass slab with figure.

Answer 1

Hint: Learn the definition of refraction then learn what happens when the light travels from denser to rarer medium or rarer to denser medium. Learn how to draw perpendicular and parallel lines.

Complete step by step answer:
Refraction of light and lateral shift using a rectangular glass slab,

In case of rectangular slab, light first travels from air to glass and then back from glass to air. So there are two refractions. First, the ray of light travels from air to glass. Hence, it travels from a rarer medium to a denser medium. So the first refracted ray bends towards normal.
After first refraction, the ray of light travels from glass to air. Hence it travels from a denser medium to a rarer medium. So the second refracted ray also called emergent ray bends away from normal.
Now, for getting lateral shift, we extend the original incidence ray and bring it towards emergent ray. Here, we can observe that the original ray and the emergent ray are parallel to each other. The angle made by the emergent ray with the normal is called the angle of emergence. And the perpendicular distance between the original incidence ray and emergent ray is called lateral shift.

Note: Refraction – when a light ray is incident on a surface separating two transparent media, the ray bends at the time of changing the medium. The angle of incidence i and the angle of refraction r follow Snell’s law
$${\displaystyle \frac{\sin i}{\sin r}}={\displaystyle \frac{v_1}{v_2}}={\displaystyle \frac{{\mu }_2}{{\mu }_1}}$$
Where $v_1$ and $v_2$ are speeds of light in media 1 and 2 respectively and ${\mu }_1$, ${\mu }_2$ are refractive indices of media 1 and 2 respectively.