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प्रश्न
The power of a lens is + 1.0 D is :
विकल्प
convex of focal length 1.0 cm
convex of focal length 1.0 m
concave of focal length 1.0 cm
concave of focal length 1.0 m
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उत्तर
Power of a lens is +1.0 D. The positive sign indicates that the focal length of the lens is positive which indicates the lens is a convex lens.
Power is P = `1/("f" ("in" "m"))`
+ 1.0 D = `1/("f" ("in" "m"))`
∴ f = 1.0 m
Hence, the correct answer is convex of focal length 1.0 m.
संबंधित प्रश्न
Which type of lens has a positive power?
Fill in the following blank with suitable word:
For converging lenses, the power is __________ while for diverging lenses, the power is ___________.
A convex lens of power 5 D and a concave lens of power 7.5 D are placed in contact with each other. What is the :
(a) power of this combination of lenses?
(b) focal length of this combination of lenses?
Focal length : metre : : power of lens : _______
The focal length of a concave lens is 20 cm. The focal length of a convex lens is 25 cm. These two are placed in contact with each other. What is the power of the combination? Is it diverging, converging or undeviating in nature?
In what unit is the power of a lens expressed?
A convex lens is a converging lens whose focal length and power are both:
When a lens is placed in a liquid, the total power of the lens is:
For a lens immersed in a medium of refractive index \[n_1\], the power is related to the focal length by:
If the lens material and the surrounding liquid have the same refractive index (\[n_2 = n_1\]), then:
