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प्रश्न
Write a 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.
Write a scientific reason.
The coin in the disappeared to have been seen from a specific location. But as soon as the water is poured into the pot to a certain level, the coin appears.
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उत्तर
- Light rays coming from the coin emerge out of water and change their direction due to the refraction of light.
- Hence, as soon as the water is poured into the pot to a certain level, the coin appears.
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संबंधित प्रश्न
What is refraction of light?
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.
Which property of light makes a pencil cast a shadow when it is held in front of a light source?
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.
What is lateral inversion? Explain by giving a suitable example.
State and explain the laws of reflection of light at a plane surface (like a plane mirror), With the help of a labelled ray-diagram. Mark the angles of 'incidence' and 'reflection' clearly on the diagram. If the angle of reflection is 47.5°, what will be the angle of incidence?
The image of an object formed by a plane mirror is:
(a) virtual
(b) real
(c) diminished
(d) upside-down
If a ray of light goes from a rarer medium to a denser medium, will it bend towards the normal or away from it?
State two effects caused by the refraction of light.
Light travels more quickly through water than through glass.
- Which is optically denser: water or glass?
- If a ray of light passes from glass into water, which way will it bend: towards the normal or away from the normal?
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?
With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is.
Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface.
Show the lateral displacement of the ray on the diagram.
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 ______.
The depth of a pond when seen from above appears to be less.
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 |
What is the cause of refraction of light when it passes from one medium to another?
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.
We can see the sun even when it is little below the horizon because of ______.
Choose and write the correct option.
If we gradually increase the angle of incidence of a ray of light passing through prism then …..
The laws of reflection hold true for ______.
Lights of different colours are used as signal for safety transport. From these, the wavelength of red light is _______ nm.
Light changes its direction when going from one transparent medium to another transparent medium. This is called _______.
Right or wrong sentence.
The incident rays and refracted rays are on opposite sides of the column.
Explain the working of a periscope.
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.
Light travels fastest in a vacuum. Why?
The bending of light as it passes from one medium to another is called ______.
The ratio of the sine of the angle of incidence to the sine of ______ is constant.
A water tank appears shallower when it is viewed from the top due to refraction.
Under what circumstances there won’t be any refraction of light when it enters from one medium to another?
How do twinkling stars occur? (or) what is the cause of the twinkling of stars?
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 |
