Advertisements
Advertisements
प्रश्न
State the condition for the following a lens has both its focal lengths equal .
Advertisements
उत्तर
If a lens has both its focal length equal medium is same on either side of lens.
संबंधित प्रश्न
Find the focal length of a lens of power −2.0 D. What type of lens is this?
What is the focal length of a convex lens of focal length 30 cm in contact with a concave lens of focal length 20 cm? Is the system a converging or a diverging lens? Ignore thickness of the lenses.
The lens mentioned in 6(b) above is of focal length 25cm. Calculate the power of the lens.
The power of a combination of two lenses X and Y is 5 D. If the focal length of lens X be 15 cm :
(a) calculate the focal length of lens Y.
(b) state the nature of lens Y.
How is the sign (+ or -) of power of a lens related to its divergent or convergent action?
On reducing the focal length of a lens, its power ______.
The power of a lens is + 1.0 D is :
A normal eye is not able to see objects closer than 25 cm because
Match the following:
| Column - I | Column - II | ||
| 1 | Retina | a | Path way of light |
| 2 | Pupil | b | Far point comes closer |
| 3 | Ciliary muscles | c | near point moves away |
| 4 | Myopia | d | Screen of the eye |
| 5 | Hypermetropia | e | Power of accommodation |
A convex lens with radii of curvature R1 = R2 is immersed in water. Assuming that the refractive indices of glass and water are 3/2 and 4/3 respectively, its focal length f1 in comparison to that in air, f, is ______.
