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प्रश्न
Explain how the formation of a rainbow occurs.
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उत्तर
- The beautiful phenomenon of the rainbow is a combination of different phenomena – dispersion, refraction, and reflection of light.
- The rainbow appears in the sky after a rain shower.
- The water droplets act as small prisms.
- When sunlight enters the water droplets present in the atmosphere, they refract and disperse the incident sunlight.
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Then they reflect it internally inside the droplet and finally again refract it.
- As a collective effect of all these phenomena, the seven coloured rainbows are observed.
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संबंधित प्रश्न
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.
What is lateral inversion? Explain by giving a suitable example.
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?
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
The image of an object formed by a plane mirror is:
(a) virtual
(b) real
(c) diminished
(d) upside-down
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 two effects caused by the refraction of light.
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?
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 ............
What is meant by the 'angle of incidence' and the 'angle of refraction' for a ray of light?
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?
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.
State two factors on which the lateral displacement of the emergent ray depends.
How does the light have to enter the glass:
to produce a large amount of bending?
A ray of light when passes from glass to air, bends towards the normal.
When a ray of light travels from water to air, it bends ............. the normal.
When a ray of light travels from air to glass, it bends .......... the normal.
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?
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?
We can see the sun even when it is little below the horizon because of ______.
The phenomenon of change in the direction of light when it passes from one transparent medium to another is called ___________.
The laws of reflection hold true for ______.
Due to _______ pencil looks bent in water, in the given experiment.
The incident rays and refracting rays are on opposite sides of the normal.
Observe the given figure and write appropriate phenomenon of light in the box.
Explain the working of a periscope.
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
The angle of incidence for a ray of light having zero reflection angle 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.
Light bends as it passes from one medium to another. What is this phenomenon called?
The ratio of the sine of the angle of incidence to the sine of ______ is constant.
Light is refracted or bent while going from one medium to another because of its ______ changes.
Which is optically denser out of the two medium M1& M2 having the refractive indices = 1.71 and 1.36 respectively?
The bottom of swimming pool appears to be less deep than the actual one because of
