Ray Optics and ...

The magnifying power of a telescope with tube length $$60cm$$ is $$5$$. What is the focal length of its eye piece?

The refractive index of the material of a concave lens is $$\mu.$$ It is immersed in a medium of refractive index $$\mu_1$$. A parallel beam of light is incident on the lens. The path of the emergent rays when $$\mu_1>\mu$$ is :

A ray of light is incident on a prism $$\mathrm{A}BC$$ of refractive index $$\sqrt{3}$$ as shown in figure.
(a) Find the angle of incidence for which the deviation of light ray by the prism $$\mathrm{A}BC$$ is minimum.
(b) By what angle the second prism must be rotated, so that the final ray suffer net minimum deviation. 

The aperture diameter of a telescope is $$5m$$. The separation between the moon and the earth is $$4\times 10^5$$ km. With light of wavelength of $$5500\overset{o}{A}$$, the minimum separation between objects on the surface of moon, so that they are just resolved, is close to?

There is a small source of light at some depth below the surface of water (refractive index $$=4/3$$) in a tank of large cross sectional surface area. Neglecting any reflection from the bottom and the absorption by water, percentage of light that emerges out of surface is (nearly):
[Use the fact that surface area of a spherical cap of height $$h$$ and radius of curvature $$r$$ is $$2\pi r h$$]  

Monochromatic light is incident on a glass prism of angle A. If the refractive index of the material of the prism is $$\mu$$, a ray incident at an angle $$\theta$$, on the face AB would get transmitted through the face AC of the prism provided

A parallel beam of light is incident from air at an angle $$\alpha $$ on the side PQ of a right-angled  triangular prism of refractive index $$n=\sqrt { 2 } $$. Light undergoes total internal reflection in the prism at the face PR when  $$\alpha $$ has minimum value of $${ 45 }^{ \circ  }$$. The angle $$\theta $$ of the prism is:

A beam of light consisting of red green and blue colours is incident on a right angled prism. The refractive index of the material of the prism for the above red, green and blue wavelengths are 1.39, 1.44 and 1.47, respectively. The prism will:

An astronomical refracting telescope will have large angular magnification and high resolution, when it has an objective lens of :

A convex lens of refractive index $$\dfrac{3}{2}$$ has a power of 2.5 D in air. If it is placed in a liquid of refractive index 2, then the new power of the lens is: