A ray of unpolarised light is incident on a glass plate of refractive index 1.54 at polarising angle, then angle of refraction is

33° 44° 57° 90°

33°

$μ = tan_{ip}$ or $tan_{ip} =1.54$ i.e., $ip = tan^{–1} 1.54 = 57°$, But $r + i_p = 90°\, ∴r = 90° - i_p$ $= 90° - 57 = 33°$