Advertisements
Advertisements
प्रश्न
The power of a lens is + 1.0 D is :
पर्याय
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
Advertisements
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
A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? Also, find the power of the lens.
Find the focal length of a lens of power −2.0 D. What type of lens is this?
The lens mentioned in 6(b) above is of focal length 25cm. Calculate the power of the lens.
Consider two statements A and B given below:
A: real image is always inverted
B: virtual image is always erect
Out of these two statements:
Which has more power : a thick convex lens or a thin convex lens, made of the same glass? Give reason for your choice.
An object of height 4 cm is placed at a distance of 15 cm in front of a concave lens of power, −10 dioptres. Find the size of the image.
Find the radius of curvature of the convex surface of a plano-convex lens, whose focal length is 0.3 m and the refractive index of the material of the lens is 1.5.
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.
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?
The power of convex lens of focal length 20 cm is ______.
