Advertisements
Advertisements
Question
If the lens is of focal length 25 cm. Calculate the power of the lens.
Advertisements
Solution
Focal length = 25 cm = 0.25 m
P = `1/0.25` = 4D
RELATED QUESTIONS
Calculate the focal length of a corrective lens having power +2D.
The lens A has a focal length of 25 cm whereas another lens B has a focal length of 60 cm. Giving reason state, which lens has more power: A or B.
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?
State the condition for the following a ray passes undeviated through the lens .
A screen is placed a distance 40 cm away from an illuminated object. A converging lens is placed between the source and the screen and its is attempted to form the image of the source on the screen. If no position could be found, the focal length of the lens
A pin of length 2.00 cm is placed perpendicular to the principal axis of a converging lens. An inverted image of size 1.00 cm is formed at a distance of 40.0 cm from the pin. Find the focal length of the lens and its distance from the pin.
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?
Find the power of a convex lens of focal length of + 25 cm.
If focal length of a convex lens is 20 cm at what is the power of the lens?
In what unit is the power of a lens expressed?
