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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.
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
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संबंधित प्रश्न
Draw a neat labelled ray diagram to show the formation of an image by a magnifying glass. State three characteristics of the image.
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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.
Copy and complete the following ray diagram.
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.
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