Advertisements
Advertisements
प्रश्न
State the condition for the following a ray passes undeviated through the lens .
Advertisements
उत्तर
If a ray passes undeviated through the lens it is incident at the optical centre of the lens.
संबंधित प्रश्न
Find the power of a concave lens of focal length 2m.
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.
Kavita from 10th is using spectacles. The power of the lenses in her spectacles is –2.5 dioptre. Answer the following questions:
1) Which lenses are used in her spectacles?
2) State the defect of vision Kavita is suffering from.
3) Find the focal length of the lenses used in her spectacles
Which type of lens has (a) a positive power, and (b) a negative power?
The power of a lens is + 0.2 D. Calculate its focal length.
A combination of lenses for a camera contains two converging lenses of focal lengths 20 cm and 40 cm and a diverging lens of focal length 50 cm. Find the power and focal length of the combination.A optical instrument in which the above arrangement of convex lens is used is a convex lens used to burn paper by focusing sunlight.
State the condition for the following a lens has both its focal lengths equal .
How is the sign (+ or -) of power of a lens related to its divergent or convergent action?
The power of a lens is +2.0 D. Find its focal length and state the kind of lens.
The focal length of a double convex lens is equal to the radius of curvature of either surface. What is the refractive index of its material?
