State Brewter's law.Show that the reflected ray and the refracted ray are perpendicular to each other,when the angle of incidene is equal to polarising angle.

Explanation

According to Brewster.s law :
`mu = tan i_(p) = (sin i_(p))/(cos i_(p))` …(i)
By Snell.s law,
`mu = (sin i)/(sin r) = (sin i_(p))/(sin r)` …(ii)
From (i) and (ii)
`sin r = cos i_(p)`
`sin r = sin (90^(@) - i_(p))`
`rArr r = 90 - i_(p)`
`i_(p) + r = 90^(@)`
`90^(@) - angle BOY) + (90 - angle COY) = 90^(@)`
`angleBOY + angle COY = 90^(@)`
`angleBOC = 90^(@)`
It means when angle of incidence is equal to angle of polarisation then refracted ray and reflected ray are perpendicular to each other.