Advertisements
Advertisements
प्रश्न
Draw images in case of a concave lens when the object is at any point on the principal axis between the lens and infinity.
उत्तर
Here the object AB is between the concave lens L and infinity and is at the principal axis. Two incident rays A and B are taken, A after refraction goes in the direction CD while the other ray B goes straight through the optical centre O. DC’ when produced backward meets the ray B at P’, which is the virtual image of P’Q’ is the image of the object PQ. The image is virtual, upright, and diminished and is on the side of the object PQ.
APPEARS IN
संबंधित प्रश्न
Define the principal focus of a concave lens.
Where must the object be placed for the image formed by a converging lens to be:
virtual, upright and larger than the object?
If an object is placed 21 cm from a converging lens, the image formed is slightly smaller than the object. If the object is placed 19 cm from the lens, the image formed is slightly larger than object. The approximate focal length of the lens is ______.
Copy and complete the diagram below to show what happens to the rays of light when they pass through the concave lens:
When an object is kept at any distance in front of a concave lens, the image formed is always:
(a) virtual, erect and magnified
(b) virtual, inverted and diminished.
(c) virtual, erect and diminished
(d) virtual, erect and same size as object
An object is 2 m from a lens which forms an erect image one-fourth (exactly) the size of the object. Determine the focal length of the lens. What type of lens is this?
The power of a concave lens is 10 D and that of a convex lens is 6 D. When these two lenses are placed in contact with each other, the power of their combination will be :
(a) +16 D
(b) +4 D
(c) −16 D
(d) −4 D
A person cannot see distant objects clearly. His vision can be corrected by using the spectacles containing:
(a) concave lenses
(b) plane lenses
(c) contact lenses
(d) convex lenses
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.
Draw neat diagram to show the
Divergent action of concave lens
