Ray Optics Test...

A point source of light moves in a straight line parallel to a plane table. Consider a small portion of the table directly below the line of movement of the source. The illuminance at this portion varies with its distance r from the source as

A point source of light Bis placed at a distance Lin front of the centre of a mirror of width dhung vertically on a wall. A man walks in front of the mirror along a line parallel to the mirror at a distance 2L from it as shown. The greatest distance over which he can see the image of the light source in the mirror is

Two plane mirrors A and B are aligned parallel to each other, as shown in the figure. A light ray is incident at an angle of 30° at a point just inside one end of A. The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflections (including the first one) before itemerges out is

A concave mirror of focal length 100cm is used to obtain the image of the sun which subtends an angle of 30\'. The diameter of the image of the sun will be

A square of side 3 cm is placed at a distance of 25 cm from a concave mirror of focal length 10cm. The centre of the square is at the axis of the mirror and the plane is normal to the axis. The area enclosed by the image of the square is

A thin rod of lengthf/3 lies along the axis of a concave mirror of focal length f. One end of its magnified image touches an end of the rod. The length of the image is

A ray of light falls on the surface of a spherical glass paper weight making an angle α with the normal and is refracted in the medium at an angle β. The angle of deviation of the emergent ray from the direction of the incident ray

A glass hemisphere of radius 0.04 m and R.I. of the material 1.6 is placed centrally over a cross mark on a paper (i) with the flat face; (ii) with the curved face in contact with the paper. In each case the cross mark is viewed directly from above. The position of the images will be

One face of a rectangular glass plate 6 cm thick is silvered. An object held 8 cm in front of the first face, forms an image 12 cm behind the silvered face. The refractive index of the glass is

A rectangular glass slab ABCD, of refractive index n₁, is immersed in water of refractive index n₂ (n₁< n₂). A ray of light in incident at the surface AB of the slab as shown. The maximum value of the angle of incidence α_max, such that the ray comes out only from the other surface CD is given by