Define 1 dioptre of power of a lens.
Dioptre is the SI unit of power of a lens is denoted by the letter D. 1 dioptre can be defined as the power of a lens of focal length 1 metre.
A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
Find the focal length of a lens of power -2.0 D. What type of lens is this?
An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed so that a sharply focused image can be obtained? Find the size and the nature of the image.
An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature, and size of the image.
The magnification produced by a plane mirror is +1. What does this mean?