Geometrical Optics

For a normal eye, the cornea of eye provides a converging power of 40 D and the least converging power of the eye lens behinf the cornea is 20 D. Using this information, the distance between the retina and the cornea-eye lens can be estimat...

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

The magnifying power of a telescope is 9. When it is adjusted for parallel rays the distance between the objective and eyepiece is 20 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

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 convex lens \(-\) concave mirror combination returns to infinity. The d...

A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its enf closer to the pole is 20 cm away from the mirror. The length of the image is

For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index.

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

A biconvex lens has a radius of curvature of magnitude 20 cm. Which one of the following options describe best the image formed of an object of height 2 cm placed 30 cm from the lens ?

A converging beam of rays is incident on a diverging lens. Having passed through the lens the rays intersect at a point 15 cm from the lens on the opposite side. If the lens is removed the point where the rays meet will move 5 cm closer to ...

A thin prism of angle 15o made of glass of refractive index \(\mu\)1 = 1.5 is combined with another prism of glass of refractive index \(\mu\)2 = 1.75. The combination of the prisms produces dispersion without deviation. The angle of the ...

A ray of light travelling in a transparent medium of refractive index \(\mu\), falls on a surface separating the medium from air at an angle of incidence of 45o. For which of the following value of \(\mu\) the ray can undergo total intern...

A lens having focal length f and aperture of diameter d forms an image of intensity I. Aperture of diameter \({d \over 2}\) in central region of lens is covered by a black paper. Focal length of lens and intensity of image now will be respe...

The speed of light in media M1 and M2 are 1.5 \(\times\) 108 m/s and 2.0 \(\times\) 108 m/s respectively. A ray of light enters from medium M1 to M2 at an incidence angle i. If the rays suffers total internal reflection, the value of i ...

A rays of light is incident on a 60o prism at the minimum deviation position. The angle of refraction at the first face (i.e., incident face) of the prism 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 cm. The diameter of the sun is 1.39 \(\times\) 109 m and its mean distance from the earth is 1.5 \(\times\) 1011 m. Wh...

Two thin lenses of focal lengths f1 and f2 are in contact and coaxial. The power of the combination is

A small coin is resting on the bottom of a beaker filled with liquid . A ray of light from the coin travels upto the surface of the liquid and moves along its surface. How fast is the light travelling in the liquid ?

A microscope is focussed on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again ?

A convex lens and a concave lens, each having same focal length of 25 cm, are put in contact to form a combination of lenses. The power in diopters of the combination is

The refractive index of the material of a prism is \(\sqrt 2\) and its refracting angle is 30o. One of the refracting surfaces of the prism is made a mirror inwards. A beam of monochromatic light entering the prism from the other face with...

A beam of light composed of red and green ray is incident obliquely at a point on the face of rectangular glass slab. When coming out on the opposite parallel face, the red green ray emerge from

An equiconvex lens is cut into two halves along (i) XOX' and (ii) YOY' as shown in the figure. Let \(f,f',\) \(f''\) be the focal lengths of the complete lens, of each half in case (i), and of each half in case (ii), respectively.
Choo...

A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will

For the given incident ray as shown in figure, the condition of total internal refraction of this ray the required refractive index of prism will be

A bulb is located on a wall. Its image is to be obtained on a parallel wall with the help of convex lens. The lens is placed at a distance d ahead of second wall, then required focal length will be

Diameter of human eye lens is 2 mm. What will be the minimum distance between two points to resolve them, which are situated at a distance of 50 meter from eye. The wavelength of light is 5000 \(\mathop A\limits^ \circ\)

A disc is placed on a surface of pond which has refractive index 5/3. A source of light is placed 4 m below the surface of liquid. The minimum radius of disc needed so that light is not coming out is,

Optical fibre are based on

For a plano convex lens (\(\mu\) = 1.5) has radius of curvature 10 cm. It is silvered on its plane surface. Find focal length after silvering

Rainbow is formed due to

A bubble in glass slab (\(\mu\) = 1.5) when viewed from one side appears at 5 cm and 2 cm from other side, then thickness of slab is

A tall man of height 6 feet, want to see his full image. Then required minimum length of the mirror will be