For an equilateral prism, it is observed that when a ray strikes grazingly at one face it emerges grazingly at the other. Its refractive index will be

Q: For an equilateral prism, it is observed that when a ray strikes grazingly at one face it emerges grazingly at the other. Its refractive index will be

Sol: i₁ = i₂ = 90° ,r₁ = r₂ = A/2 = 30°

$\large \mu = \frac{sini_1}{sinr_1} $

$\large \mu = \frac{sin90^o}{sin30^o} $

μ = 2