Advertisements
Advertisements
प्रश्न
On reducing the focal length of a lens, its power ______.
पर्याय
Decreases
Increases
Does not change
First increases then decreases.
उत्तर
On reducing the focal length of a lens, its power increases.
APPEARS IN
संबंधित प्रश्न
Calculate the focal length of a corrective lens having power +2D.
What is the unit of power of a lens? Define the unit of power of a lens.
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 convex lens produces a double size real image when an object is placed at a distance of 18 cm from it. Where should the object be placed to produce a triple size real image?
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?
A lens forms an upright and diminished image of an object, irrespective of its position. What kind of lens is this? Draw an outline ray diagram to show the formation of the image. State the position and one more characteristic of the image.
If there is a convex lens of focal length 75 cm and a concave lens of focal length 40 cm, then calculate their combined power and combined focal length.
An object is kept at a distance of 1m from a lens of power +2D:
- Identify the type of lens.
- Calculate its focal length and distance of the image formed.
