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प्रश्न
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.
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उत्तर
Object distance, u = -20 cm
Focal length, f = -20 cm (concave lens)
For a lens, magnification is
m = `"v"/"u"`
`therefore "m" = (-10)/-20`
∴ m = + 0.5
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 magnification by a lens is -3. Name the lens and state how are u and v related?
The magnification by a lens is +0.5. Name the lens and state how are u and v related?
What are conjugate foci?
Define the term magnifying power of a simple microscope. How does it depend on the focal length of the lens used?
Name the lens used as a magnifying glass.
Why is the focal length of the lens, used as a magnifying glass, kept short?
Will the image formed by a magnifying glass be real or virtual?
Define magnification produced by a lens. State its unit.
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?
