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प्रश्न
(a) Draw a sketch to show how a lens is able to produce an image of the sun on a paper screen.
(b)(i) Would you regard the rays from the sun as being divergent, parallel or convergent?
(ii) What is the name given to the point where such rays meet after they have passed through the lens?
(iii) How does the image of the sun sometimes burn a paper screen?
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उत्तर
(a)
(b)
(i) Rays from sun can be regarded as parallel rays.
(ii) The point is called 'Focus'.
(iii) A convex lens is used to focus the sun rays on a piece of paper to burn a piece of paper. A large amount of heat gets concentrated at a point and is sufficient to burn the piece of paper.
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संबंधित प्रश्न
In figure, (a) and (b), F1 and F2 are the two foci of thin lenses and AB is the incident ray. Complete the diagram to show the path of the ray AB after refraction through each lens.
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| (a) |
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| (b) |
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through ______.
Distinguish between a real and a virtual image.
A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.
State the condition of the following:
A ray passes undeviated through the lens.
In the following diagram the object and the image formed by the respective lenses are shown. Complete the ray diagram, and locate the focus. Find the focal length of the lens.
Make the rrect choices in the following items :
ln fig, , a real image of a point objert O is formed, Which of the following statements is true about each of the arrangements?
(i) The object is at the principle focus of the lens
(ii) The focal length of the lens is 17 cm
(iii) lf the mirror is moved so that it is 6 cm from the lens image will also move
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.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
