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प्रश्न
Distinguish between a convex lens and concave lens. Which of the two is a converging lens : convex lens of concave lens?
उत्तर
| Convex Lens | Concave Lens |
| 1.A convex lens converges or concentrates the light rays to a point. | 1. A concave lens diverges the rays passing through it. |
| 2.A convex lens has a real focus. | 2.A concave lens has a virtual focus. |
| 3.A convex lens has a positive focal length. | 3.A concave lens has a negative focal length. |
A convex lens is a converging lens .
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संबंधित प्रश्न
An object is placed at a distance of 15 cm from a concave lens of focal length 30 cm. List four characteristics (nature, position, etc.) of the image formed by the lens.
Complete the following table:
| Instrument | Number of Convex Lenses |
Use |
| Simple Microscope | .............. | .............. |
| Compound Microscope | .............. | .............. |
| Telescope | .............. | .............. |
State any two uses of convex lenses.
An object is placed at a distance equal to 2f in front of a convex lens. Draw a labelled ray diagram to show the formation of image. State two characteristics of the image formed.
Where should an object be placed in front of a convex lens to get a real image of the size of the object?
The focal length of a lens is positive. In this case, state the kind of lens.
State two applications of a convex lens.
What happens to the image formed by a convex lens if its lower part is blackened?
Why do we say that the ‘2F’ and ‘F’ points of a convex lens can be regarded as a sort of ‘turning points’ as far as the nature of the image formed by it is concerned?
