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प्रश्न
Choose and write the correct option.
If we gradually increase the angle of incidence of a ray of light passing through prism then …..
विकल्प
Angle of deviation goes on decreasing.
Angle of deviation decreases but after certain value of incident angle, deviation angle increases
Angle of deviation goes on increasing.
Angle of deviation increases but after certain value of incident angle deviation angle decreases.
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उत्तर
Angle of deviation decreases but after certain value of
incident angle, deviation angle increases.
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संबंधित प्रश्न
Name the phenomenon responsible for the following effect:
When we sit in front of a plane mirror and write with our right hand, if appears in the mirror that we are writing with the left hand.
Fill in the following blank with a suitable word:
When light is reflected, the angles of incidence and reflection are ............ .
Where is the image when you look at something in a mirror?
Which type of reflection of light leads to the formation of images?
A boy with a mouth 5 cm wide stands 2 m away from a plane mirror. Where is his image and how wide is the image of his mouth?
Define the following terms used in the study of reflection of light by drawing a labelled ray-diagram:
(a) Incident ray
(b) Point of incidence
(c) Normal
(d) Reflected ray
(e) Angle of incidence
(f) Angle of reflection
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 man stands 10 m in front of a large plane mirror. How far must the walk before he is 5 m away from his image?
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 ______.
Explain how to read the following message which was found on some blotting paper:
If a ray of light goes form a denser medium to a rarer medium, will it bend towards the normal or away from the normal?
State two effects caused by the refraction of light.
Why does a ray of light bend when it travels from one medium to another?
Light travels more quickly through water than through glass.
If a ray of light passes from glass into water, which way will it bend : towards the normal or away from the normal?
Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface.
With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab, the emergent ray is parallel to the incident ray.
Show the lateral displacement of the ray on the diagram.
State two factors on which the lateral displacement of the emergent ray depends.
The depth of a pond when seen from above appears to be less.
Light travels at a lower speed in water than in air.
When a ray of light travels from water to air, it bends ............. the normal.
The diagram (figure) given below shows two parallel rays 1 and 2 incident on (a) a concave mirror, (b) a convex mirror. Draw the reflected rays and mark the focus by the symbol F.
Fill in the blank and Explain the completed sentences.
The change in ______ of light rays while going from one medium to another is called refraction.
A real image is formed by the light rays after reflection or refraction when they:
- actually meet or intersect with each other.
- actually converge at a point.
- appear to meet when they are produced in the backward direction.
- appear to diverge from a point.
Which of the above statements are correct?
Write scientific reason.
The coin disappears in a vessel as it is seen from a specific location. But as soon as the water is poured into the vessel to a certain level, the coin appears.
Observe the given figure and write appropriate phenomenon of light in the box.
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 angle of incidence from air to glass at the point O on the hemispherical glass slab is.
Which object use the reflection of light?
The phenomenon of light passing through the object is called ______.
The ratio of the sine of the angle of incidence to the sine of ______ is constant.
Twinkling of stars and Mirage are the two phenomena occurring due to refraction.
Match the following:
| Column I | Column II | ||
| 1. | r > 90 | a. | Light gazes at the surface of separation between the two modes. |
| 2. | r = 90 | b. | No refraction. |
| 3. | r < 90 | c. | Refracted ray away from the normal |
The bottom of swimming pool appears to be less deep than the actual one because of
When a ray of light travels normal to the given surface, then the angle of refraction is ______.
