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प्रश्न
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.
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उत्तर
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.
संबंधित प्रश्न
What is a magnifying glass?
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 -3. Name the lens and state how are u and v related?
What are conjugate foci?
Why is the focal length of the lens, used as a magnifying glass, kept short?
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.
Show with the help of a ray diagram, the path of the ray when incident normally on the first surface of the glass block, through the block and the liquid.
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.
Write an expression for the magnifying power of a simple microscope. How can it be increased?
State two uses of magnifying glass.
