Ray Optics

A ray of light incidents at an angle of $60^{\circ}$ on the first face of a prism. The angle of the prism is $30^{\circ}$ and its second face is silvered. If the light ray inside the prism retraces its path after reflection from the second ...

When an object is placed infront of a convex mirror at a distance ' $u$ ' from the pole of the mirror such that the size of the image is ' $n$ ' times that of the object. Then, the object distance ' $u=$

The ratio of the focal lengths of a convex lens when kept in air and when it is immersed in a liquid is $1: 2$. If the refractive index of the material of the lens is 1.5 , then the refractive index of the liquid is

A light ray falls on a rectangular glass slab as shown in the figure. If total internal reflection occurs at the vertical face of the slab at point $B$, the refractive index of glass is

If the least distance of distinct vision for a boy is 35 cm , then the lens to be used by the boy for correcting the defect of his eye is

A light ray incidents on an equilateral prism made of material of refractive index $\sqrt{3}$. Inside the prism, if the light ray moves parallel to the base of the prism, then the angle of incidence of the light ray is

Images of same size are formed by a convex lens when an object is placed either at 20 cm or 10 cm distance from the lens. The focal length of the lens is

Two thin convex lenses are kept in contact coaxially. If the focal length of the combination of the lenses is 4 cm and sum of the focal lengths of the two lenses is 18 cm , then the focal length of the lens of low power is

If the far point of a short sighted person is 400 cm , then the power of the lens required to enable him to see very distant objects clearly is

When a convex lens is immersed in two different liquids of refractive indices 1.25 and 1.5 , the ratio of the focal lengths of the lens is $5: 16$. The refractive index of the material of the lens is

A person can see objects clearly when they lie between 40 cm and 400 cm from his eye. In order to increase the maximum distance of distant vision to infinity the type of lens and power of correction lens required respectively, are

When a convex lens is immersed in a liquid of refractive index equal to $80 \%$ of the refractive index of the material of the lens. The focal length of the lens increases by $100 \%$. The refractive index of the liquid is

A ray of light travels from an optically denser to rare medium. The critical angle for the media is $C$. The maximum possible deviation of the ray will be

The angle of polarisation for a medium with respect to air is $60^{\circ}$. The critical angle of this medium with respect to air is

The focal length of the objective lens of a telescope is 30 cm and that of its eye lens is 3 cm . It is focussed on a scale at a distance 2 m from it. The distance of objective lens from eye lens to see the clear image is

An object lying 100 cm inside water is viewed normally from air. If the refractive index of water is $\frac{4}{3}$, then the apparent depth of the object is

An object is placed at a distance of 18 cm in front of a mirror. If the image is formed at a distance of 4 cm on the other side, then focal length, nature of the mirror and nature of image are respectively

The minimum deviation produced by a hollow prism filled with a certain liquid is found to be $30^{\circ}$. The light ray is also, found to be refracted at an angle of $30^{\circ}$. Then, the refractive index of the liquid is

The focal length of a thin converging lens in air is 20 cm . When thefens is immersed in a liquid, it behaves like a concave lens of power 1 D . If the refractive index of the material of the lens is 1.5 . The refractive index of the liquid...

The magnifying power of a telescope with tube length 60 cm is 5 . Then, the focal length of its eye piece is

A needle is lying at the bottom of a water tank of height 12 cm. The apparent depth of the needle measured by a microscope is 9 cm . If the water is replaced by a liquid of refractive index of 1.5 of same height, the distance through which ...

A ray is incident from a medium of refractive index 2 into a medium of refractive index 1. The critical angle is

The radii of curvature of a double convex lens are 4 cm and 8 cm . If the refractive index of the material of the lens is 1.5 , the focal length of the lens is nearly.

Assertion (A) The focal length of lens does
not change when red light is replaced by blue
light.
Reason (R) The focal length of lens does not
depend on colour of light used.

Light of wavelength \(300 \mathrm{~nm}\) in medium \(A\) enters into medium \(B\) through a plane surface. If the frequency of light is \(5 \times 10^{14} \mathrm{~Hz}\) and the ratio of speed in medium \(A\) to that in medium \(B\) is $$4 ...