Define the principal focus of a concave mirror .

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(a)

Why do we prefer a convex mirror as a rear view mirror in vehicles?

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(a)

Find the focal length of a convex mirror whose radius of curvature is 32cm.

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The refractive index of diamond is 2.42.What is the meaning of this statement?

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Define 1dioptre of power of lens.

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One - half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.

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An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed.

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How do you find the rough focal length of a convex lens? Is the same method applicable to a concave lens?

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What are the factors that determine the focal length of a lens?

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Identify the device used as a spherical mirror or lens in following cases, when the image formed is virtual and erect in each case.
(a) Object is placed between device and its focus, image formed is enlarged and behind it.
(b) Object is placed between the focus and device, image formed is enlarged and on the same side as that of the object.
(c) 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.
(d) Object is placed between infinity and device, image formed is diminished and between pole and focus, behind it.

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(a)

A convex lens of focal length 20 cm can produce a magnified virtual as well as real image. Is this a correct statement? If yes, where shall the object is placed in each case for obtaining these images?

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How are power and focal length of a lens related? You are provided with two lenses of focal length 20 cm and 40 cm respectively. Which lens will you use to obtain more convergent light?

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Draw a ray diagram showing the path of rays of light when it enters with oblique incidence (i) from air into water; (ii) from water into air.

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(a)

Draw the following diagram, in which a ray of light is incident on a concave.convex mirror, on your answer sheet. Show the path of this ray, after reflection, in each case.

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(a)