Advertisements
Advertisements
प्रश्न
Draw images in case of a concave lens when the object is at infinity.
उत्तर
When the object is at infinity, the incident ray is taken parallel to the principal axis. As shown in the figure, the image is virtual and is formed at the focus F1 It is diminished (small) in size.
APPEARS IN
संबंधित प्रश्न
Due to gradual weakening of ciliary muscles and diminishing flexibility of the eye lens a certain defect of vision arises. Write the name of this defect. Name the type of lens required by such persons to improve the vision. Explain the structure and function of such a lens.
Construct ray diagrams to illustrate the formation of a virtual image using a diverging lens.
When sunlight is concentrated on a piece of paper by a spherical mirror or lens, then a hole can be burnt in it. For doing this, the paper must be placed at he focus of:
(a) either a convex mirror or convex lens
(b) either a concave mirror or concave lens
(c) either a concave mirror or convex lens
(d) either a convex mirror or concave lens
A concave lens has focal length 15 cm. At what distance should the object from the lens be placed so that it forms an image at 10 cm from the lens? Also find the magnification produced by the lens.
Complete the following sentence:
A short-sighted person cannot see ............ objects clearly. Short-sightedness can be corrected by using ........... lenses.
Choose the correct alternative and rewrite the following:
Inside water, an air bubble behaves ....................
State three characteristics of the image of an extended source, formed by a concave lens.
In figure give below of thin concave lens, F1 and F2 are its foci, complete the path of the given ray of light after it emerges out of the lens.
Identify the device used as a spherical mirror or lens in following case, when the image formed is virtual and erect in case.
Object is placed between infinity and device, image formed is diminished and between focus and optical centre on the same side as that of the object.
Distinguish between:
Concave Lens and Convex Lens
