Ray optics practice · Mixed difficulty

If the refractive angles of two prisms made of crown glass are ${10^0}$ and ${20^0}$ respectively, then the ratio of their colour deviation powers will be

To obtain a magnified image at the distance of distinct vision with simple microscope, where should the object be placed?

The focal length of a convex lens depends upon

Which of the following is used in optical fibres

An object is viewed through a compound microscope and appears in focus when it is $\mathrm{5 mm}$ away from the objective lens. When a sheet of transparent material $\mathrm{3 mm}$ thick is placed between the objective and the microscope, the objective lens has to be moved $\mathrm{1 mm}$ to bring the object back into the focus. The refractive index of the transparent material is

An achromatic combination of lenses is formed by joining

Statement I : The refractive index of diamond is $\sqrt{6}$ and that of liquid is $\sqrt{3}$. If the light travels from diamond to the liquid, it will be totally reflected when the angle of incidence is $30^{\circ}$.

Statement II : $n=\frac{1}{\sin C}$, where $n$ is the refractive index of diamond with respect to liquid.

Refractive index of a medium is $\mu$. The incidence angle is twice that of refracting angle. The angle of incidence is

A beam of monochromatic light is refracted from vacuum into a medium of refractive
index 1.5. The wavelength of refracted light will be

When a biconvex lens of glass having refractive index $\mathrm{1}\mathrm{.47}$ is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index

The spectrum obtained from a sodium vapour lamp is an example of

A concave mirror has a focal length $f$. A real object is placed on axis at distance $\frac{{3f}}{2}$ in front of its pole, the image produced by the mirror is at distance

When the distance between the object and the screen is more than $4 \mathrm{~F}$, we can obtain image of an object on the screen for the two positions of a lens. It is called displacement method. In one case, the image is magnified and in the other case it is diminished. Then, the ratio of the size of image to the diminished image is

For the myopic eye, the defect cured by

The astronomical telescope consists of objective and eye-piece. The focal length of the objective is

A concave mirror has a focal length $20 \mathrm{~cm}$. The distance between the two positions of the object for which the image size is double of the object size is

In a converging lens as a magnifying glass, the object must be placed

In order to increase the angular magnification of a simple microscope, one should increase

A small telescope has an objective lens of focal length $150 \mathrm{~cm}$ and an eye piece of focal length $5 \mathrm{~cm}$. If this telescope is used to view a $100 \mathrm{~m}$ high tower $3 \mathrm{~km}$ away, find the height of the final image when it is formed $25 \mathrm{~cm}$ away from the eye piece.

A convex lens of focal length $\mathrm{30 cm}$ produces $\mathrm{5 }\,\mathrm{times}$ magnified real image of an object. What is the object distance?

What focal length should be the reading spectacles have for a person for whom the least distance of distinct vision is $50 \mathrm{~cm}?$

For normal vision, what is distance of object from eye?

Assertion: Dispersion of light occurs because velocity of light in a material depends upon its colour.
Reason: The dispersive power depends only upon the material of the prism, not upon the refractive angle of the prism.

Light travels in two media $A$ and $B$ with speeds $1.8\,\, \times \,\,{10^8}\,\,m{s^{ - 1}}$ and $2.4\,\, \times \,\,{10^8}\,\,m{s^{ - 1}}$ respectively. Then the critical angle between them is

Assertion (A): A ray of light travels from first medium to second medium. In first medium angle of ray with normal is $i_1=30^{\circ}$ and in second medium $i_2=60^{\circ}$. Then second medium is rarer medium

Reason (R): Refractive index of frist medium with respect to second medium is $\frac{\sin 30^{\circ}}{\sin 60^{\circ}}$

A transparent cube of 0.21 m edge contains a small air bubble. Its apparent distance when viewed through one face of the cube is $\mathrm{0}\mathrm{.10 m}$ and when viewed from the opposite face is $\mathrm{0}\mathrm{.04 m}$. The actual distance of the bubble from the second face of the cube is

Ability of the eye to see objects at all distances is called

A ray of light is incident on a plane mirror along the direction given by vector $A = 2\,\mathrm{\hat i}{\mkern 1mu} \, - \,\,3\,\mathrm{\hat j}{\mkern 1mu} {\mkern 1mu} \, + \,\,4\,\mathrm{\hat k}$. Find the unit vector along reflected ray. Take normal to mirror along the direction of vector $B = 3\,\mathrm{\hat i}{\mkern 1mu} \,\,\, - \,\,\,6\,\mathrm{\hat j}{\mkern 1mu} {\mkern 1mu} \,\, + \,\,2\,\mathrm{\hat k}$.

The chromatic aberration in lenses becomes due to

A) A diver under water, looks obliquely at a fisherman standing on the bank of a lake. The fisherman look shorter to the driver than what he actually is.

B) A convex mirror always produces a virtual image independent of location of the real object.