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. Draw two rays from the object AB and complete the diagram to locate the position of the image CD. Also mark on the diagram the position of eye from where the image can be viewed.
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.
Why is the focal length of the lens, used as a magnifying glass, kept short?
Name the lens for which magnification is always less than 1.
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)?
Copy and complete the following ray diagram.
(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?
Write an expression for the magnifying power of a simple microscope. How can it be increased?
