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प्रश्न
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 ______.
विकल्प
2 cm
4 cm
10 cm
22 cm
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उत्तर
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 4 cm.
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संबंधित 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.
A wall reflects light and a mirror also reflects light. What difference is three in the way they reflect light?
The angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
The figure given alongside shows the image of a clock as seen a plane mirror. The correct time is:
Figure
(a) 2.25
(b) 2.35
(c) 6.45
(d) 9.25
A ray of light goes from water into air. Will it bend towards the normal or away from the normal?
When a ray of light passes from air into glass, is the angle of refraction greater than or less than the angle of incidence?
What is meant by the 'angle of incidence' and the 'angle of refraction' for a ray of light?
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 |
Draw a diagram showing the refraction of a light ray from water to glass. Label on it the incident ray, the angle of incidence (/), and the angle of refraction (r)
What is atmospheric reflection? Explain with the help of a labelled diagram that the position of a star as seen by us is not its true position.
The laws of reflection hold true for ______.
The incident rays and refracting rays are on opposite sides of the normal.
Write scientific reason.
The bottom of a pond appears raised.
Observe the given figure and write appropriate phenomenon of light in the box.
Explain with diagrams how refraction of incident light takes place from
- rarer to denser medium
- denser to rarer medium
- normal to the surface separating the two media.
Numerical problems.
The speed of light in water is 2.25 × 108 ms–1. If the speed of light in vacuum is 3 × 108 ms–1, calculate the refractive index of water.
The refractive index of four substances A, B, C, and D are 1.31, 1.43, 1.33, 2.4 respectively. The speed of light is maximum in
A star appears twinkling into the sky because of the reflection of light by the atmosphere.
Twinkling of stars and Mirage are the two phenomena occurring due to refraction.
The bottom of swimming pool appears to be less deep than the actual one because of
