Advertisements
Advertisements
प्रश्न
What is refraction of light?
What is refraction of light? Explain with the help of an example.
Explain the refraction of light.
Advertisements
उत्तर
- Light changes its direction when going from one transparent medium to another transparent medium. This change in direction is called the refraction of light.
- For example, the coin appears to disappear in a vessel when viewed from a specific angle. But as soon as the water is poured into the vessel at a certain level, the coin appears. This phenomenon is because light rays coming from the coin emerge out of the water and change their direction due to the refraction of light.
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, it appears in the mirror that we are writing with the left hand.
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.
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?
What type of reflection of light takes place from a cinema screen?
Define the following terms used in the study of reflection of light by drawing a labelled ray-diagram:
- Incident ray
- Point of incidence
- Normal
- Reflected ray
- Angle of incidence
- Angle of reflection
With the help of a labelled ray-diagram, describe how a plane mirror forms an image of a point source of light placed in front of it. State the characteristics of the image formed in a plane mirror.
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.
The angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
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 man sits in an optician's chair looking into plane mirror which is 2 m away from him and views the image of a chart which faces the mirror and is 50 cm behind his head. How far away from his eyes does the chart appear to be?
If a ray of light goes from a rarer medium to a denser medium, will it bend towards the normal or away from it?
A ray of light goes from water into air. Will it bend towards the normal or away from the normal?
As light rays pass from water into glass, are they refracted towards the normal or away from the normal?
Why does a ray of light bend when it travels from one medium to another?
Fill in the following blank with suitable word:
Light bends when is passes from water into air. We say that it is ............
With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is.
- With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab, the emergent ray is parallel to the incident ray.
- Show the lateral displacement of the ray on the diagram.
Show the lateral displacement of the ray on the diagram.
State two factors on which the lateral displacement of the emergent ray depends.
A vertical ray of light strikes the horizontal surface of some water:
- What is the angle of incidence?
- What is the angle of refraction?
How does the light have to enter the glass:
to produce a large amount of bending?
How does the light have to enter the glass:
for no refraction to happen?
Water is optically denser than glass.
Air is optically .......... than glass.
When a ray of light travels from water to air, it bends ............. the normal.
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 small air bubble in a glass block when seen from above appears to be raised because of ______.
List in proper sequence the steps of the experiment for determining the approximate focal length of a given concave mirror by obtaining the image of a distant object.
Due to _______ pencil looks bent in water, in the given experiment.
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.
Observe the given figure and write appropriate phenomenon of light in the box.
State whether true or false. If false, correct the statement.
The angle of deviation depends on the refractive index of the glass.
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 four substances A, B, C, and D are 1.31, 1.43, 1.33, 2.4 respectively. The speed of light is maximum in
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?
Light travels fastest in a vacuum. Why?
Light is refracted or bent while going from one medium to another because of its ______ changes.
A star appears twinkling into the sky because of the reflection of light by the atmosphere.
Mirage is an example of refraction and the total internal reflection of light.
Which is optically denser out of the two medium M1& M2 having the refractive indices = 1.71 and 1.36 respectively?
In refraction of light through a glass slab, the directions of the incident ray and the refracted ray are ______.
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 ______.
