A card sheet divided into squares each of size 1 mm² is being viewed at a distance of 9 cm through a magnifying glass (a converging lens of focal length 10 cm) held close to the eye. What is the magnification produced by the lens? 

A card sheet divided into squares each of size 1 mm² is being viewed at a distance of 9 cm through a magnifying glass (a converging lens of focal length 10 cm) held close to the eye. The angular magnification of the lens is:

The linear magnification and angular magnification in the microscope have similar magnitude when the image is at a distance:

Figure shows a biconvex lens (of refractive index 1.50) in contact with a liquid layer on top of a plane mirror. A small needle with its tip on the principal axis is moved along the axis until its inverted image is found at the position of the needle. The distance of the needle from the lens is measured to be 45.0 cm. The liquid is removed and the experiment is repeated. The new distance is measured to be 30.0 cm. What is the refractive index of the liquid?

Light incident normally on a plane mirror attached to a galvanometer coil retraces backward as shown in the figure. A current in the coil produces a deflection of 3.5° of the mirror. What is the displacement of the reflected spot of light on a screen placed 1.5 m away?

A Cassegrain telescope uses two mirrors as shown in the figure. Such a telescope is built with the mirrors 20 mm apart. If the radius of curvature of the large mirror is 220 mm and the small mirror is 140 mm, where will the final image of an object at infinity be?

An angular magnification (magnifying power) of 30X is desired using an objective of focal length 1.25 cm and an eyepiece of focal length 5 cm. The separation between the objective lens and the eyepiece should be:

Digital movie projectors work on the principle of:

Day and night settings for rearview mirrors use:

When a beam of light is incident on a plane mirror, it is found that a real image is formed. The incident beam must be:

An object is placed symmetrically between two plane mirrors inclined at an angle of 72^o, then the total number of images observed is:

A person 1.6 m tall is standing at the centre between two walls three metres high. What should be the minimum size of a plane mirror fixed on the wall in front of him if he is to see the full height of the wall behind him?

While capturing solar energy for commercial purposes, we use:

A concave mirror of focal length f produces an image n times the size of the object. If the image is real, then the distance of the object from the mirror is:

An object placed in front of a concave mirror of focal length 0.15 m produces a virtual image that is twice the size of the object. The position of the object with respect to the mirror is:

When a light ray from a rarer medium is refracted into a denser medium, its:

A narrow, paraxial beam of light is converging towards a point I on a screen. A plane plate of glass of thickness t and a refractive index $\mathrm{\mu }$ is introduced in the path of the beam. The convergence point is shifted by:

The length of a vertical pole at the surface of a lake of water $\left(\mu =\frac{4}{3}\right)$ is 24 cm. Then, to an under-water fish just below the water surface, the tip of the pole appears to be:

A microscope is focused on a coin lying at the bottom of a beaker. The microscope is now raised by 1 cm. To what depth should water be poured into the beaker so that the coin is again in focus?

(The refractive index of water is $\frac{4}{3}$)

Two transparent media A and B are separated by a plane boundary. The speed of light in medium A is 2.0 x 10⁸ ms^-1 and in medium B is 2.5 x 10⁸ ms^-1. The critical angle for which a ray of light going from A to B suffers total internal reflection is:

Which of the following is the possible application of fibre optics?

The least distance between a point object and its real image formed by a convex lens of focal length F is:

The plane faces of two identical plano-convex lenses, each having a focal length of 40 cm, are placed against each other to form a usual convex lens. The distance from this lens at which an object must be placed to obtain a real, inverted image with a magnification of '-1' is:

Two thin lenses of focal lengths 20 cm and -20 cm are placed in contact with each other. The combination has a focal length equal to:

If in a plano-convex lens, the radius of curvature of the convex surface is 10 cm and the focal length of the lens is 30 cm, the refractive index of the material of the lens will be:

A glass concave lens is placed in a liquid in which it behaves like a convergent lens. If the refractive indices of glass and liquid with respect to air are ${}_a{\mu }_g$ and ${}_a{\mu }_l$ respectively, then

The diameter of the aperture of a plano-convex lens is 6 cm and its maximum thickness is 3 mm. If the velocity of light in the material of the lens is 2 x 10⁸ m/s, its focal length is (approximately):

When an object is at a distance of u₁ and u₂ from a lens, a real image and a virtual image is formed respectively having the same magnification. The focal length of the lens is:

A concave lens of focal length f produces an image (1/x) of the size of the object. The distance of the object from the lens is:

A thin equiconvex glass lens of refractive index 1.5 has a power of 5D. When the lens is immersed in a liquid of refractive index $\mathrm{\mu }$, it acts as a divergent lens of focal length 100 cm. The value of $\mathrm{\mu }$ of liquid is: