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
A ray of light strikes a plane mirror such that its angle of incidence is 30°. What angle does the reflected ray make with the mirror surface?
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?
What type of reflection of light takes place from a cinema screen?
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?
State the uses of plane mirrors.
The image in a plane mirror is virtual and laterally inverted. What does this statement mean?
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 ______.
Explain how to read the following message which was found on some blotting paper:
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?
When a ray of light passes from air into glass, is the angle of refraction greater than or less than the angle of incidence?
State whether the following statement is true or false:
Refraction occurs because light slows down in denser materials.
Why does a ray of light bend when it travels from one medium to another?
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’?
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?
State two factors on which the lateral displacement of the emergent ray depends.
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.
Light travelling from a denser medium to a rarer medium along a normal to the boundary:
(a) is refracted towards the normal
(b) is refracted away from the normal
(c) goes along the boundary
(d) is not refracted
A vertical ray of light strikes the horizontal surface of some water:
- What is the angle of incidence?
- What is the angle of refraction?
The depth of a pond when seen from above appears to be less.
Light travels at a lower speed in water than in air.
When a ray of light travels from air to glass, it bends .......... the normal.
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?
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.
Due to _______ pencil looks bent in water, in the given experiment.
The incident rays and refracting rays are on opposite sides of the normal.
Explain the working of a periscope.
The deviation of light ray from its path when it travels from one transparent medium to another transparent medium is called ______.
If a beam of red light and a beam of violet light are incident at the same angle on the inclined surface of a prism from air medium and produce angles of refraction r and v respectively, which of the following is correct?
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.
A water tank appears shallower when it is viewed from the top due to refraction.
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 |
The bottom of swimming pool appears to be less deep than the actual one because of
