Advertisements
Advertisements
प्रश्न
If the numerical value of the power of this lens is 10 D, what is its focal length in the Cartesian system ?
उत्तर
Since, power of a lens is given by the relation
`P=1/f` (in metres)
p = 10 D (given)
`10 = 1/f`
`f = 1/10`
`f= 0.1 m`
Therefore, the focal length of the lens is 0.1 m as the lens is concave in nature.
APPEARS IN
संबंधित प्रश्न
Explain with the help of a diagram, why the concave lens is also called a diverging lens.
Which type of lenses are:
thinner in the middle than at the edges?
Which type of lens is
a diverging lens? Explain your answer with diagrams.
Construct ray diagrams to illustrate the formation of a virtual image using a converging lens,
An object is placed on the axis of a lens. An image is formed by refraction in the lens. For all positions of the object on the axis of the lens, the positions of the image are always always between the lens and the object.State three characteristics of the image.
How will you differentiate between a convex and a concave lens by looking at
- a distant object,
- a printed page?
Explain the working of an astronomical telescope using refraction of light.
An object is placed at a distance 24 cm in front of a convex lens of focal length 8 cm.
(i) What is the nature of the image so formed?
(ii) Calculate the distance of the image from the lens.
(iii) Calculate the magnification of the image.
Express power of a concave lens of focal length 50 cm with its sign.
Define the term principal foci as applied to a concave lens. Illustrate your answer with the aid of proper diagrams. Show the focal length of the lens in the diagram.
