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प्रश्न
State whether the following statement is true of false:
A student says that we can see an object because light from our eyes is reflected back by the object.
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उत्तर
False.We can see an object because light, on being reflected from the object, is scattered and diffused.
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संबंधित प्रश्न
| Column I | Column II | Column III | |
| 1 | Dispersion | Long-sightedness | Twinkling of stars |
| 2 | Refraction | Splitting of white light into component colours | Convex lens |
| 3 | Hypermetropia | Change in the direction of the ray of light due to change in medium | Spectrum of seven colours |
Fill in the following blank with a suitable word:
When light is reflected, the angles of incidence and reflection are ............ .
A ray of light strikes a plane mirror such that its angle of incidence is 30°. What angle does the reflected ray make with the mirror surface?
What are the important differences between looking at a photograph of your face and looking at yourself in a plane mirror?
The boy walks towards the mirror at a speed of 1 m/s. At what speed does his image approach him?
An object is placed 20 cm in front of a plane mirror. The mirror is moved 2 cm towards the object. The distance between the positions of the positions of the original and final images seen in the mirror is ______.
A man sits in an optician's chair looking into plane mirror which is 2 m away from him and views the image of a chart which faces the mirror and is 50 cm behind his head. How far away from his eyes does the chart appear to be?
A ray of light strikes a plane mirror PQ at an angle of incidence of 30°, is reflected from the plane mirror and then strikes a second plane mirror QR placed at right angles to the first mirror. The angle of reflection at the second mirror is ______.
Why does a ray of light bend when it travels from one medium to another?
Show the lateral displacement of the ray on the diagram.
When a ray of light travels from water to air, it bends ............. the normal.
Match the Following
| Column A | Column B |
| (a) white Light | (1) Convex mirror |
| (b) Refraction | (2) Concave mirror |
| (c) Virtual images | (3) refraction |
| (d) Real images | (4) spectrum |
| (e) Prism | (5) ray of light from glass to air |
Define the principal focus of a concave mirror.
Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3 × 108 m s−1.
Choose the correct option from given alternative:
A real image is formed by the light rays after reflection or refraction when they:
(A) actually meet or intersect with each other.
(B) actually converge at a point
(C) appear to meet when they are produced in the backward direction.
(D) appear to diverge from a point.
Which of the above statements are correct?
What is refractive index?
When light passes from one medium to another the ray gets bent. This property of light is called ______.
How do twinkling stars occur? (or) what is the cause of the twinkling of stars?
