Advertisements
Advertisements
प्रश्न
Write an expression for the magnifying power of a simple microscope. How can it be increased?
Advertisements
उत्तर
Is the ratio of the angle of the image subtended at the eye to the angle subtended by the object at the eye when lying at least a distance of distinct vision.
m = 1 + `D/f` where f is the focal length of the lens.
One way to get more magnifying power is to use a lens with a shorter focal length.
APPEARS IN
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.

Draw a neat labelled ray diagram to show the formation of an image by a magnifying glass. State three characteristics of the image.
Where is the object placed with respect to the principal focus of a magnifying glass, so as to see its enlarged image? Where is the image obtained?
What information about the nature of image is real or virtual, do you get from the sign of magnification + or -?
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?
Name the lens for which magnification can be 1. For what position of the object will the magnification be 1?
Copy and complete the following ray diagram.

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.
What is a magnifying glass (or a simple microscope)? Draw a ray diagram to show how a convex lens may be used as a magnifying glass. Where should the object be placed? State three characteristics of the image formed.
