NEET UG 2010 — Optics

The speed of light in media $\mathbf{M}_1$ and $\mathrm{M}_2$ is $1.5 \times 10^8 \mathrm{~m} / \mathrm{s}$ and $2.0 \times 10^8 \mathrm{~m} / \mathrm{s}$ respectively. A ray of light enters from medium $\mathrm{M}_1$ to $\mathrm{M}_2$ at an incidence angle $i$. If the ray suffers total internal reflection, the value of $i$ is

A ray of light travelling in a transparent medium of refractive index $\mu$ falls, on a surface separating the medium from air at an angle of incidence of $45^{\circ}$. For which of the following value of $\mu$ the ray can undergo total internal reflection?

A ray of light is incident on a $60^{\circ}$ prism at the minimum deviation position. The angle of refraction at the first face (ie, incident face) of the prism is

A lens having focal length $f$ and aperture of diameter $\mathrm{d}$ forms an image of intensity $I$. Aperture of diameter $\frac{\mathrm{d}}{2}$ in central region of lens is covered by a black paper. Focal length of lens and intensity of image now will be respectively