Advertisements
Advertisements
Question
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.
Advertisements
Solution
A magnifying glass is a convex (or converging) lens of B short focal length mounted in a plastic or wooden frame provided with a handle. It is used to see small objects or to read small letters.

The ray diagram showing the use of a convex lens as a magnifying glass is given in the figure.
The object should be placed in front of the lens between its optical centre and focus.
RELATED QUESTIONS
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
A lens forms an erect, magnified, and virtual image of an object. Name the device which uses this principle.
What is a magnifying glass?
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 -?
An object is placed at a distance of 20 cm in front of a concave lens of focal length 20 cm. find: the magnification of image.
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?
An object is placed in front of a lens between its optical centre and the focus and forms a virtual, erect, and diminished image. Draw a ray diagram to show the formation of the image with the above-stated characteristics.
What is a simple microscope or a magnifying glass? Draw a ray diagram to show its function.
