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प्रश्न
Which of the following can form a virtual image which is always smaller than the object?
(a) a plane mirror
(b) a convex lens
(c) a concave lens
(d) a concave mirror
उत्तर
a concave lens
A concave lens always forms a virtual image, smaller than the size of the object.
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.
Where must the object be placed for the image formed by a converging lens to be:
real, inverted and smaller than the object?
State whether concave lens has a real focus or a virtual focus.
Things always look small on viewing through a lens. What is the nature of the lens?
Which type of lens is :
a converging lens, and which is
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
The power of a converging lens is 4.5 D and that of a diverging lens is 3 D. The power of this combination of lenses placed close together is :
(a) +1.5D
(b) +7.5D
(c) −7.5D
(d) −1.5D
At what distance from a concave lens of focal length 20 cm a 6 cm tall object be placed so as to obtain its image at 15 cm from the lens? Also calculate the size of the image formed.
Draw a ray diagram to justify your answer for the above situation and label it.
Explain the working of an astronomical telescope using refraction of light.
When an object is kept within the focus of a concave mirror, an enlarged image is formed behind the mirror. This image is :
