Question

The Brewster's angle for the glass-air interface is (54.74)°. If a ray of light passing from air to glass strickes at an angle of incidence 45°, then the angle of refraction is ______.
`[tan (54.74)° = sqrt2, sin 45 = 1/sqrt2]`

Options

• `sin^-1 (sqrt2)`

• sin^-1(1)

• sin^-1(0.5)

• sin^-1`(1/sqrt2)`

Answer 1

The Brewster's angle for the glass-air interface is (54.74)°. If a ray of light passing from air to glass strickes at an angle of incidence 45°, then the angle of refraction is sin^-1(0.5).

Explanation:

According to Brewster's law, refractive index of glass,

µ₂ = tan (i_p)

= tan(54.74)° = `sqrt2`

From Snell's law,

µ₁ sin i = µ₂ sin r

1 × sin (45°) = `sqrt2` sin r

`1/(sqrt2 xx sqrt2)` = sin r

sin r = 0.5

r = sin^-1(0.5)