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प्रश्न
State the nature and position of the object on the principal axis to obtain a real and magnified image.
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उत्तर
Lens is convex; the position of the object is between F and 2F.
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संबंधित प्रश्न
What is a lens?
Explain optical centre of a lens with the help of proper diagram(s).
State the condition when a lens is called an equi-convex or equi-concave.
For an object placed at a distance 20 cm in front of a convex lens, the image is at a distance 20 cm behind the lens. The focal length of the convex lens is ______.
State the condition of the following:
A ray passes undeviated through the lens.
Define the term focus of a lens.
Fig. shows two rays of light Op and OQ coming from an object at the bottom of a pond, incident on the water surface.
(a) Mark on the diagram
(i) The angle of incidence of ray OP,
(ii) The angle of refraction of ray Op,
(iii) The position of image of the object as seen from above.
(iv) An approximate path of the ray OQ.
(b) Explain, why do the rays of light change directions on passing from water to air.
(c) A fish in water sees everything outside the water by rays of light entering its eye in a small cone of light. Draw a diagram and explain how does this happen.
A lens forms the image of an object placed at a distance of 45 cm from it on a screen placed at a distance 90 cm on the other side of it. Name the kind of lens.
In the following diagram, L1 and L2 are the two convex lense placed at separation equal to the sum of focal lengths of the two lenses. A and B are the two rays of light incident on the lens L1. Complete the path of rays till they emerge out of the lens L2.
What principles have you used in completing the diagram?
Mixture of red + blue + green is passed through a convex lens as shown in the diagram below. State whether the ray passes through a single point or through different points on the principal axis after refraction.
