Ray Optics Questions

In a certain camera, a combination of four similar thin convex lenses are arranged axially in contact. Then the power of the combination and the total magnification in comparison to the power ($p$) and magnification ($m$) for each lens will be, respectively:

A microscope has an objective of focal length $2\text{cm}$, eyepiece of focal length $4\text{cm}$ and the tube length of $40\text{cm}$. If the distance of distinct vision of eye is $25\text{cm}$, the magnification in the microscope is:

Which of the following is not due to total internal reflection?

A biconvex lens has a radius of curvature of magnitude $20\text{cm}$. Which one of the following options describes best the image formed of an object of height $2\text{cm}$ placed $30\text{cm}$ from the lens? (Assume refractive index $\mu =1.5$)

An air bubble in a glass slab with refractive index $1.5$ is $5\text{cm}$ deep when viewed from one surface and $3\text{cm}$ deep when viewed from the opposite face. The thickness (in cm) of the slab is:

Two identical glass (${\mu }_g=3/2$) equiconvex lenses of focal length $f$ each are kept in contact. The space between the two lenses is filled with water (${\mu }_w=4/3$). The focal length of the combination is:

A person can see clearly objects only when they lie between $50\text{cm}$ and $400\text{cm}$ from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens, the person has to use, will be:

The angle of incidence for a ray of light at a refracting surface of a prism is $45^{\circ }$. The angle of prism is $60^{\circ }$. If the ray suffers minimum deviation through the prism, the angle of minimum deviation and refractive index of the material of the prism respectively, are:

Match the corresponding entries of column 1 with column 2. [Where $m$ is the magnification produced by the mirror]Column 1: (A) $m=-2$, (B) $m=-1/2$, (C) $m=+2$, (D) $m=+1/2$ Column 2: (a) Convex mirror, (b) Concave mirror, (c) Real image, (d) Virtual image

An astronomical telescope has objective and eyepiece of focal lengths $40\text{cm}$ and $4\text{cm}$ respectively. To view an object $200\text{cm}$ away from the objective, the lenses must be separated by a distance:

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:

In an astronomical telescope in normal adjustment, a straight black line of the length $L$ is drawn on the objective lens. The eye-piece forms a real image of this line. The length of this image is $I$. The magnification of the telescope is:

The angle of a prism is 'A'. One of its refracting surfaces is silvered. Light rays falling at an angle of incidence $2A$ on the first surface returns back through the same path after suffering reflection at the silvered surface. The refractive index $\mu$, of the prism is:

If the focal length of objective lens is increased then magnifying power of:

A ray of light is incident at an angle $i$ on one face of a prism of angle $A$ (small) and emerges normally from the opposite face. If the refractive index is $\mu$, the angle $i$ is nearly equal to:

A concave mirror of focal length $f_1$ is placed at a distance of $d$ from a convex lens of focal length $f_2$. A beam of light coming from infinity and falling on this combination returns to infinity. The distance ‘$d$ ’ must equal:

The magnifying power of a telescope is $9$. When it is adjusted for parallel rays the distance between the objective and eyepiece is $20\text{cm}$. The focal length of lenses are:

When a biconvex lens of glass having refractive index $1.47$ is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index:

For the angle of minimum deviation of a prism to be equal to its refracting angle ($A$), the prism must be made of a material whose refractive index ($\mu$):

A rod of length $10\text{cm}$ lies along the principal axis of a concave mirror of focal length $10\text{cm}$ in such a way that its end closer to the pole is $20\text{cm}$ away. The length of the image is:

A boy is trying to start a fire by focusing Sunlight on a piece of paper using an equiconvex lens of focal length $10\text{cm}$. The diameter of the Sun is $1.39\times 10^9\text{m}$ and its mean distance from the earth is $1.5\times 10^{11}\text{m}$. What is the diameter of the Sun's image on the paper?

Two thin lenses of focal lengths $f_1$ and $f_2$ are in contact and coaxial. The power of the combination is:

Assertion: The resolving power of a telescope is more if the diameter of the objective lens is more.Reason: Objective lens of large diameter collects more light.

Assertion: Diamond glitters brilliantly.Reason: Diamond does not absorb sunlight.

Assertion: By roughening the surface of a glass sheet its transparency can be reduced.Reason: Glass sheet with rough surface absorbs more light.

The apparent depth of water in cylindrical water tank of diameter $2R\text{cm}$ is reducing at the rate of $x\text{cm/minute}$ when water is being drained out at a constant rate. The amount of water drained in $\text{c.c.}$ per minute is ($n_1=\text{refractive index of air}$, $n_2=\text{refractive index of water}$):

A telescope has an objective lens of focal length $200\text{cm}$ and an eye piece with focal length $2\text{cm}$. If this telescope is used to see a $50\text{meter}$ tall building at a distance of $2\text{km}$, what is the height of the image of the building formed by the objective lens?

What should be the maximum acceptance angle at the air-core interface of an optical fibre if $n_1$ and $n_2$ are the refractive indices of the core and the cladding, respectively?