Advertisements
Advertisements
प्रश्न
What are conjugate foci?
Advertisements
उत्तर
Two points lying on the principal axis such that the image of an object kept at such point is formed on the other point, are called conjugate foci.
संबंधित प्रश्न
The speed of light in air is 3 × 108 m s-1. Calculate the speed of light in glass. The refractive index of glass is 1.5
The following diagram shows an object AB and a converging lens L with foci F1 and F2 State three characteristics of the image in relation to the object.

A lens forms an erect, magnified, and virtual image of an object. Where is the object placed in relation to the lens?
What is a magnifying glass?
If the magnification produced by a lens is - 0.5, the correct statement is ______.
The focal length of a convex lens is 25 cm. At what distance from the optical centre of the lens an object be placed to obtain a virtual image of twice the size?
A convex lens produces on a screen an image twice the size of the object. If the position of image and object be interchanged, what will be the magnification then?
How is the magnification (m) produced by a lens related to the object distance (u) and the image distance (v)?
An erect, magnified, and a virtual image is formed when an object is placed between the optical centre and principal focus of a lens.
(i) Name the lens.
(ii) Draw a ray diagram to show the formation of the image with the above-stated characteristics.
(i) Draw a ray diagram to show how the lens can be used as a ‘magnifying glass’? State the nature of the lens.
(ii) In what respect does the image in (i) above different from the image formed by a concave lens?
