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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
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Draw a neat diagram to explain the action of a convergent (convex) lens as a reading glass (or magnifying glass). State the characteristics of the image formed.
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(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?
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