Q. 100. A transparent semicylinder has refractive index μ=2 . A parallel beam of light is incident on its plane surface making an angle of 45∘ with the surface. The incident beam extends from O to A on the plane surface. Find the maximum width OA (in terms of radius R of the cylinder) so that no ray suffers total internal reflection at the curved surface. [ O is the centre of the circular cross section of the cylinder]
