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प्रश्न
Write scientific reason.
The bottom of a pond appears raised.
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उत्तर
- The rays of light coming from the bottom of a pond bend away from the normal as they travel from water (denser medium) to air (rarer medium).
- Hence, they appear to come from a point above the actual point from which they come. Therefore, the bottom of the pond appears raised.
APPEARS IN
संबंधित प्रश्न
| 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 |
Fill in the following blank with a suitable word:
When light is reflected, the angles of incidence and reflection are ............ .
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?
An extended object in the form of an arrow pointing upward has been placed in front of a plane mirror. Draw a labelled ray-diagram to show the formation of its image.
What is meant by 'reflection of light'?
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
Explain why, though both a plane mirror and a sheet of paper reflect light but we can see the image of our face in a plane mirror but not in a sheet of paper.
Explain how to read the following message which was found on some blotting paper:
When a ray of light passes from air into glass, is the angle of refraction greater than or less than the angle of incidence?
A ray of light passes from air into a block of glass. Does it bend towards the normal or away from it?
As light rays pass from water into glass, are they refracted towards the normal or away from the normal?
In which material do you think light rays travel faster-glass or air?
Light travels more quickly through water than through glass.
Which is optically denser : water or glass?
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.
How does the light have to enter the glass:
for no refraction to happen?
The speed of light is more in glass than in water.
Light travels at a lower speed in water than in air.
Image is formed by a mirror due to refraction of light.
Water is optically .......... than air.
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 passes from medium 1 to medium 2. Which of the following quantities of the refracted ray will differ from that of the incident ray: Speed, intensity, frequency, wavelength?
Define the principal focus of a concave mirror.
Explain how the formation of a rainbow occurs.
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.
Assertion and reasoning type
- Assertion: If the refractive index of the medium is high (denser medium) the velocity of the light in that medium will be small
- Reason: Refractive index of the medium is inversely proportional to the velocity of the light
You are given water, mustard oil, glycerine and kerosene. In which of these media a ray of light incident obliquely at same angle would bend the most?
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.
A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water. Will the pencil appear to be bent to the same extent, if instead of water we use liquids like, kerosene or turpentine. Support your answer with reason.
A ray of light traveling in medium 1 strikes and travels into another transparent medium 2. If the speed of light is greater in medium 1, the ray will ______.
Mirage is an example of refraction and the total internal reflection of light.
Under what circumstances there won’t be any refraction of light when it enters from one medium to another?
The bottom of swimming pool appears to be less deep than the actual one because of
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.
When a ray of light travels normal to the given surface, then the angle of refraction is ______.
