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प्रश्न
Observe the given figure and name the following.
| Ray AB | |
| Ray NM | |
| Ray MD | |
| ∠ r |
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उत्तर
| Ray AB | Incident ray |
| Ray NM | Refracted ray |
| Ray MD | Emergent ray |
| ∠ r | Angle of refraction |
संबंधित प्रश्न
What is refraction of light?
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.
Where is the image when you look at something in a mirror?
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?
Which type of reflection of light leads to the formation of images?
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 ______.
State whether the following statement is true or false:
Refraction occurs because light slows down in denser materials.
A ray of light travelling in air is incident on a rectangular glass block and emerges out into the air from the opposite face. Draw a labelled ray diagram to show the completer path of this ray of light. Mark the two points where the refraction of light takes place. What can you say about the final direction of ray of light?
What is meant by the 'angle of incidence' and the 'angle of refraction' for a ray of light?
When a light ray passes from air into glass, what happens to its speed? Draw a diagram to show which way the ray of light bends.
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.
A vertical ray of light strikes the horizontal surface of some water:
What is the angle of incidence?
A vertical ray of light strikes the horizontal surface of some water:
What is the angle of refraction?
Light travels at a lower speed in water than in air.
Air is optically .......... than glass.
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.
We can see the sun even when it is little below the horizon because of ______.
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.
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.
Due to _______ pencil looks bent in water, in the given experiment.
Identify the wrong figure from the following.
The speed of light varies in different media.
Write scientific reason.
A pencil appears to be broken near the surface of water.
Observe the given figure and write appropriate phenomenon of light in the box.
Numerical problems.
The speed of light in water is 2.25 × 108 ms–1. If the speed of light in vacuum is 3 × 108 ms–1, calculate the refractive index of water.
What is refractive index?
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?
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 phenomenon of light passing through the object 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.
Assertion: The air bubble shines in water.
Reason: Air bubble shines due to the refraction of light.
In refraction of light through a glass slab, the directions of the incident ray and the refracted ray are ______.
When a ray of light travels normal to the given surface, then the angle of refraction is ______.
