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प्रश्न
An object is placed in front of a converging lens. Obtain the conditions under which the magnification produced by the lens is
- negative and
- positive.
उत्तर
- Magnification is negative for the real image formed by a convex lens.
- Magnification is positive for the virtual image formed by a convex lens.
संबंधित प्रश्न
The focal length of a convex lens is 25 cm. What is its power?
What do you understand by the power of a lens? Name one factor on which the power of a lens depends.
A diverging lens has a focal length of 0.10 m. The power of this lens will be:
Express the power (with sign) of a concave lens of focal length 20 cm.
A thin converging lens is formed with one surface convex and the other plane. Does the position of image depend on whether the convex surface or the plane surface faces the object?
A 5.0 diopter lens forms a virtual image which is 4 times the object placed perpendicularly on the principal axis of the lens. Find the distance of the object from the lens.
A diverging lens of focal length 20 cm and a converging lens of focal length 30 cm are placed 15 cm apart with their principal axes coinciding. Where should an object be placed on the principal axis so that its image is formed at infinity?
Which lens has more power a thick lens or a thin lens?
Assertion and reasoning type
- Assertion: Myopia is due to the increase in the converging power of eye lens.
- Reason: Myopia can be corrected with the help of concave lens.
Define power of a lens. What is its unit? One student uses a lens of focal length 50 cm and another of –50 cm. What is the nature of the lens and its power used by each of them?
