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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
| 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.
Which property of light makes a pencil cast a shadow when it is held in front of a light source?
Where is the image when you look at something in a mirror?
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 is the difference between regular reflection of light and diffuse reflection of light?
State and explain the laws of reflection of light at a plane surface (like a plane mirror), With the help of a labelled ray-diagram. Mark the angles of 'incidence' and 'reflection' clearly on the diagram. If the angle of reflection is 47.5°, what will be the angle of incidence?
The angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
The image formed by a plane mirror is :
(a) virtual, behind the mirror and enlarged.
(b) virtual, behind the mirror and of the same size as the object.
(c) real, at the surface of the mirror and enlarged.
(d) real, behind the mirror and of the same size as the object.
The figure given alongside shows the image of a clock as seen in a plane mirror. The correct time is:
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?
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 ______.
When a ray of light passes from air into glass, is the angle of refraction greater than or less than the angle of incidence?
What is meant by the ‘angle of incidence’ for a ray of light?
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.
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
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.
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 ______.
Choose and write the correct option.
If we gradually increase the angle of incidence of a ray of light passing through prism then …..
The size of image of an object by a convex lens of focal length 20 cm is observed to be reduced to `1/3` rd of its size . Find the distance of the object from the optical centre of the lens .
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.
Right or wrong sentence.
The incident rays and refracted rays are on opposite sides of the column.
Write scientific reason.
The sun appears on the western horizon for some time after sunset.
Explain the working of a periscope.
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.
Which surface will not reflect most of the light falling on them?
Light bends as it passes from one medium to another. What is this phenomenon called?
Mirage is an example of refraction and the total internal reflection of light.
Twinkling of stars and Mirage are the two phenomena occurring due to refraction.
Assertion: The air bubble shines in water.
Reason: Air bubble shines due to the refraction of light.
Why a pencil partly immersed in water appears to be bent at the water surface.
The part of light that enters into the other medium and travels in a straight path but in a direction different from its initial direction is called:
The ray that enters the second medium after crossing the boundary is called the:
When a light ray passes from a denser medium to a rarer medium, it bends:
