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प्रश्न
We can see the sun even when it is little below the horizon because of ______.
पर्याय
Reflection of light
Refraction of light
Dispersion of light
Absorption of light
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उत्तर
We can see the Sun even when it is little below the horizon because of refraction of light.
Explanation:
We can see the Sun even when it is a little below the horizon because of atmospheric refraction. The Earth’s atmosphere bends the light from the Sun upwards towards the eye of the observer. Even though the Sun itself might be just below the horizon line, the light is refracted or bent by the atmosphere, thus making the Sun appear to be visible.
संबंधित प्रश्न
What is refraction of light?
Where is the image when you look at something in a mirror?
The angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
The image of an object formed by a plane mirror is:
(a) virtual
(b) real
(c) diminished
(d) upside-down
The image formed by a plane mirror is :
(a) virtual, behind the mirror and enlarged.
(b) virtual, behind the mirror and of the same size as the object.
(c) real, at the surface of the mirror and enlarged.
(d) real, behind the mirror and of the same size as the object.
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?
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?
In which material do you think light rays travel faster-glass or air?
State whether the following statement is true or false:
Refraction occurs because light slows down in denser materials.
Explain with the help of a labelled ray diagram, why a pencil partly immersed in water appears to be bent at the water surface. State whether the bending of pencil will increase or decrease if water is replaced by another liquid which is optically more dense than water. Give reason for your answer.
When a ray of light travelling in glass enters into water obliquely ______.
A ray of light passes from a medium X to another medium Y. No refraction of light occurs if the ray of light hits the boundary of medium Y at an angle of:
(a) 0°
(b) 45°
(c) 90°
(d) 120°
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 |
Draw suitable diagrams to illustrate how a beam of light incident parallel to the principal axis is reflected by:
(a) a concave mirror, and (b) a convex mirror
A light ray suffers reflection and refraction at the boundary in passing from air to water. Draw a neat labelled ray diagram to show it.
A ray of light A incident from air suffers partial reflection and refraction at the boundary of water.
- Complete the diagram showing (i) the reflected ray B and (ii) the refracted ray C.
- How are the angles of incidence i and refraction r related?
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.
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.
List four characteristics of the image formed by a concave lens of focal length 20 cm when the object is placed at a distance of 40 cm from its optical centre.
The size of image of an object by a convex lens of focal length 20 cm is observed to be reduced to `1/3` rd of its size . Find the distance of the object from the optical centre of the lens .
Write scientific reason.
The bottom of a pond appears raised.
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.
What is refractive index?
The angle of incidence from air to glass at the point O on the hemispherical glass slab is.
Noor, a young student, was trying to demonstrate some properties of light in her Science project work. She kept ‘X’ inside the box (as shown in the figure) and with the help of a laser pointer made light rays pass through the holes on one side of the box. She had a small butter-paper screen to see the spots of light being cast as they emerged.
Her friend noted the following observations from this demonstration:
- Glass is optically rarer than air.
- Air and glass allow light to pass through them with the same velocity.
- Air is optically rarer than glass.
- Speed of light through a denser medium is faster than that of a rarer medium.
- The ratio: sin of angle of incidence in the first medium to the ratio of sin of angle of refraction in the second medium, gives the refractive index of the second material with respect to the first one.
Which one of the combinations of the above statements given below is correct.
Which surface will not reflect most of the light falling on them?
The phenomenon of light passing through the object is called ______.
The bending of light as it passes from one medium to another is called ______.
A star appears twinkling into the sky because of the reflection of light by the atmosphere.
Why a pencil partly immersed in water appears to be bent at the water surface.
The bottom of swimming pool appears to be less deep than the actual one because of
The ray that enters the second medium after crossing the boundary is called the:
When a ray of light is incident along the normal on the surface separating two media:
The constant \[\frac{\sin i}{\sin r}\] for a given pair of media is called the:
The absolute refractive index of a medium is given by:
