Advertisements
Advertisements
प्रश्न
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.
Advertisements
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.
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 |
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.
If an object is placed at a distance of 10 cm in from of a plane mirror, how far would it be from its image?
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.
Which type of reflection of light leads to the formation of images?
The boy walks towards the mirror at a speed of 1 m/s. At what speed does his image approach him?
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.
The image in a plane mirror is virtual and laterally inverted. What does this statement mean?
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 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 ______.
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 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 travelling along a normal is ...............refracted.
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'? Draw a labelled ray diagram to show the refraction of light.
How does the light have to enter the glass:
for no refraction to happen?
The depth of a pond when seen from above appears to be less.
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.
A small air bubble in a glass block when seen from above appears to be raised because of ______.
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.
Explain how the formation of a rainbow occurs.
Write scientific reason.
The sun appears on the western horizon for some time after sunset.
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.
The refractive index of a transparent medium is always greater than ______.
In the above diagram light is travelling through different media. It is noted by a scientist that ∠1= ∠3 = ∠4 but ∠2 < ∠1. Which of the following statement would be correct?
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.
The bending of light as it passes from one medium to another is called ______.
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 ______.
The ratio of the sine of the angle of incidence to the sine of ______ is constant.
A star appears twinkling into the sky because of the reflection of light by the atmosphere.
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.
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 ______.
