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प्रश्न
Define the term magnifying power of a simple microscope. How does it depend on the focal length of the lens used?
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उत्तर
The magnifying power of a simple microscope is defined as the ratio of the angle subtended by the image at the eye to the angle subtended by the object at the eye if it is assumed to be placed at the least distance of distinct vision.
Shorter the focal length of the lens used, larger is its magnifying power.
संबंधित प्रश्न
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.

Name the lens used as a magnifying glass.
Why is the focal length of the lens, used as a magnifying glass, kept short?
What information we seek by the linear magnification of the image when it is positive or negative?
Name the lens for which magnification is always less than 1.
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.
An object AB is placed between 2F1 and F1 on the principal axis of a convex lens as shown in the diagram. Copy the diagram and using three rays starting from point A, obtain the image of the object formed by the lens.

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.
(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?
