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प्रश्न
Identify the wrong figure from the following.
पर्याय
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उत्तर
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संबंधित प्रश्न
What is refraction of light?
| 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 |
Name the phenomenon responsible for the following effect:
When we sit in front of a plane mirror and write with our right hand, it appears in the mirror that we are writing with the left hand.
The letter F is placed in front of a plane mirror:
- How would its image look like when seen in a plane mirror?
- What is the name of the phenomenon involved?
Write the word AMBULANCE as it would appear when reflected in a plane mirror. Why is it sometimes written in this way (as its mirror image) on the front of an ambulance?
What are the important differences between looking at a photograph of your face and looking at yourself in a plane mirror?
A wall reflects light and a mirror also reflects light. What difference is three in the way they reflect light?
State the uses of plane mirrors.
The image in a plane mirror is virtual and laterally inverted. What does this statement mean?
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.
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?
A ray of light travelling in glass emerges into air. State whether it will bend towards the normal or away from the normal.
State two effects caused by the refraction of light.
State whether the following statement is true or false:
Refraction occurs because light slows down in denser materials.
Fill in the following blank with suitable word:
Light bends when is passes from water into air. We say that it is ............
What is meant by ‘refraction of light’?
A ray of light travelling in air is incident on a rectangular glass block and emerges out into the air from the opposite face. Draw a labelled ray diagram to show the completer path of this ray of light. Mark the two points where the refraction of light takes place. What can you say about the final direction of ray of light?
A coin in a glass tumbler appears to rise as the glass tumbler is slowly filled with water. Name the phenomenon responsible for this effect.
Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface.
Light travels at a lower speed in water than in 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)
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?
A small air bubble in a glass block when seen from above appears to be raised because of ______.
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.
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 phenomenon of change in the direction of light when it passes from one transparent medium to another is called ___________.
The speed of light varies in different media.
Write scientific reason.
A pencil appears to be broken near the surface of water.
State whether true or false. If false, correct the statement.
The angle of deviation depends on the refractive index of the glass.
The refractive index of a transparent medium is always greater than ______.
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.
Mirage is an example of refraction and the total internal reflection of light.
Twinkling of stars and Mirage are the two phenomena occurring due to refraction.
Why a pencil partly immersed in water appears to be bent at the water surface.
A ray of light starting from diamond is incident on the interface separating diamond and water. Draw a labelled ray diagram to show. the refraction of light in this case.
