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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 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.
A lens forms an erect, magnified, and virtual image of an object. Name the device which uses this principle.
Draw a neat labelled ray diagram to show the formation of an image by a magnifying glass. State three characteristics of the image.
An illuminated object lies at a distance 1.0 m from a screen. A convex lens is used to form the image of the object on a screen placed at a distance of 75 cm from the lens. Find:
- the focal length of the lens, and
- the magnification.
The magnification by a lens is +0.5. Name the lens and state how are u and v related?
Define magnification produced by a lens. State its unit.
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?
