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GK Questions and Answers on Lenses and Mirrors

Mirrors are polished metal that forms images and lenses are transparent glass having curved sides which are used in optical instruments. This article deals with the uses and applications of mirrors and lenses in the form of question and answers.
Oct 23, 2019 13:03 IST
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GK Quiz on Mirror and lenses
GK Quiz on Mirror and lenses

Mirror is a reflecting surface or a polished metal that forms images. It works on the principle of reflection of light. When a man stands in front of the mirror, light from all parts of the body is reflected from the mirror back to the eyes and a virtual image appears to be formed behind the mirror. Mirror is of two types; concave and convex mirror where as lens is a transparent or a piece of glass having a curved side for the dispersion of light rays. Lenses are used in all optical instruments, like microscopes, telescopes, cameras, projectors etc. It is also of two type’s concave and convex lens. This article deals with mirror and lenses in the form of question and answers.

1. In the case of a concave mirror, the image of an object is
(a) Real, erect and diminished when the object lies beyond the centre of curvature.
(b) Real, inverted and of the same size as the object when it lies between the centre of curvature and focus.
(c) Real, inverted and diminished when the object lies beyond the centre of curvature.
(d) Not real, large and unproportional.
Ans. c
2. To increase the magnifying power of a telescope, the focal length of
(a) Objective lens should be increased.
(b) Objective lens should be decreased.
(c) Eye-piece lens should be increased.
(d) Eye-piece lens should be decreased.
Ans. d
3. Why the colour of the ocean appears blue?

(a) Because the sunlight falling on it is reflected.
(b) Because the sunlight falling on it is refracted.
(c) Because the sunlight falling on it is absorbed.
(d) Because the sunlight falling on it is scattered.
Ans. d
4. What is the power of concave lens?

(a) Positive
(b) Negative
(c) Both
(d) None of the above
Ans. b
5. Which glasses or lens are used to correct the short sighted eye defect?

(a) Concave Lens
(b) Convex Lens
(c) Bipolar Lens
(d) None of the above
Ans. a

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6. In projectors which lenses are used?

(a) Convex lens
(b) Concave lens
(c) Bipolar lens
(d) Both (a) and (b)
Ans. a
7. Due to which phenomena the stick if immersed in water appears to be bent?
(a) Reflection
(b) Dispersion
(c) Refraction
(d) Scattering
Ans. c
8. Due to which phenomena light rays emerging from a cinema machine spread wide on the screen?
(a) Dispersion
(b) Diffraction
(c) Scattering
(d) Refraction
Ans. b
9. Dental mirror is what type of a mirror?

(a) Convex mirror
(b) Concave mirror
(c) Plane mirror
(d) Both (b) and (c)
Ans. d
10. What type of a mirror is used in anti-shop-lifting-devices?

(a) Concave mirror
(b) Convex mirror
(c) Plane mirror
(d) None of the above
Ans. b

From this article we will come to know the applications and uses of lenses and mirrors in the form of MCQs.

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