Advertisements
Advertisements
Question
Explain how the formation of a rainbow occurs.
Advertisements
Solution
- 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.
-
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.
APPEARS IN
RELATED QUESTIONS
Where is the image when you look at something in a mirror?
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?
What is meant by 'reflection of light'?
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.
Explain how to read the following message which was found on some blotting paper:
If a ray of light goes from a rarer medium to a denser medium, will it bend towards the normal or away from it?
Which phenomenon of light makes the water to appear shallower than it really is?
Why does a ray of light bend when it travels from one medium to another?
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.
With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is.
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 ray of light passes from a medium X to another medium Y. No refraction of light occurs if the ray of light hits the boundary of medium Y at an angle of:
(a) 0°
(b) 45°
(c) 90°
(d) 120°
Water is optically denser than glass.
A ray of light when passes from glass to air, bends towards the normal.
Air is optically .......... than glass.
When a ray of light travels from air to glass, it bends .......... the normal.
What do you understand by refraction of light?
What is the cause of refraction of light when it passes from one medium to another?
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?
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.
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 ______.
The incident rays and refracting rays are on opposite sides of the normal.
The speed of light varies in different media.
Observe the given figure and name the following.
| Ray AB | |
| Ray NM | |
| Ray MD | |
| ∠ r |
Why does a ray of light bend when it travels from one medium to another?
Assertion and reasoning type
- Assertion: If the refractive index of the medium is high (denser medium) the velocity of the light in that medium will be small
- Reason: Refractive index of the medium is inversely proportional to the velocity of the light
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?
The deviation of light ray from its path when it travels from one transparent medium to another transparent medium is called ______.
The angle of incidence from air to glass at the point O on the hemispherical glass slab is.
Which object use the reflection of light?
The bending of light as it passes from one medium to another is called ______.
The ratio of the sine of the angle of incidence to the sine of ______ is constant.
Twinkling of stars and Mirage are the two phenomena occurring due to refraction.
