HC Verma Chapter 18 Problem 1 – Angle of refraction at air-glass interface

Given

Light in air hits glass (n=1.5) at 30 deg to normal

Find

Angle of refraction

Formula

Snell’s law: n1 sin i = n2 sin r

Solution

sin r = (1 x sin30)/1.5 = 0.5/1.5 = 0.333; r = 19.47 deg

Answer

r = 19.5 deg

Diagram / Concept

Ray bends toward normal entering denser medium

Notes

n_glass ~ 1.5; angle always measured from normal