If the light moving in a straight-line bends by a small but fixed angle, it may be a case of

Mark the correct options.

Which of the following (referred to a spherical mirror) do (does) not depend on whether the rays are paraxial or not?

The image of an extended object, placed perpendicular to the principal axis of a mirror, will be erect if

A convex lens forms a real image of a point object placed on its principal axis. If the upper half of the lens is painted black,

Consider three converging lenses L1, L2 and L3 having identical geometrical construction. The index of refraction of L1 and L2 are μ1 and μ2 respectively. The upper half of the lens L3 has a refractive index μ2 (figure 18-Q3). A point object O is imaged at O1 by the lens L1 and at O2 by the lens L2 placed in same position. If L3 is placed at the same place,

A screen is placed at a distance 40 cm away from an illuminated object. A converging lens is place between the source and the screen and it is attempted to form the image of the source on the screen. If no position could be found, the focal length of the lens