Advertisements
Advertisements
प्रश्न
If the lens is of focal length 25 cm. Calculate the power of the lens.
Advertisements
उत्तर
Focal length = 25 cm = 0.25 m
P = `1/0.25` = 4D
संबंधित प्रश्न
The focal length of a convex lens is 25 cm. What is its power?
The optician's prescription for a spectacle lens is marked +0.5 D. What is the:
(a) nature of spectacle lens?
(b) focal length of spectacle lens?
A converging lens has a focal length of 50 cm. The power of this lens is:
State the condition for the following a ray passes undeviated through the lens .
A symmetric double convex lens is cut in two equal parts by a plane containing the principal axis. If the power of the original lens was 4 D, the power of a divided lens will be
Focal length : metre : : power of 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.
The above lens has a focal length of 10 cm. The object of height 2 mm is placed at a distance of 5 cm from the pole. Find the height of the image.
The power of convex lens of focal length 20 cm is ______.
In what unit is the power of a lens expressed?
