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प्रश्न
Fill in the blank:
Very fine particles mainly scatter ………… colored light.
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उत्तर
Very fine particles mainly scatter blue colored light.
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संबंधित प्रश्न
Give a scientific reason:
Danger signal lights are red in colour.
Why can’t we see clearly through fog?
Suppose you are inside the water in a swimming pool near an edge. A friends is standing on the edge. Do you find your friend taller or shorter than his usual height?
A convex lens is made of a material having refractive index
\[1 \cdot 2\] Both the surfaces of the lens are convex. If it is dipped into water (μ = 1.33), it will behave like
A point object O is placed on the principal axis of a convex lens of focal length f = 20 cm at a distance of 40 cm to the left of it. The diameter of the lens is 10 cm. An eye is placed 60 cm to right of the lens and a distance h below the principal axis. The maximum value of h to see the image is
A concave mirror having a radius of curvature 40 cm is placed in front of an illuminated point source at a distance of 30 cm from it. Find the location of the image.
A point source S is placed midway between two converging mirrors having equal focal length f as shown in figure. Find the values of d for which only one image is formed.
A converging mirror M1, a point source S and a diverging mirror M2 are arranged as shown in figure. The source is placed at a distance of 30 cm from M1. The focal length of each of the mirrors is 20 cm. Consider only the images formed by a maximum of two reflections. It is found that one image is formed on the source itself. (a) Find the distance between the two mirrors. (b) Find the location of the image formed by the single reflection from M2.
Light falls from glass (μ = 1.5) to air. Find the angle of incidence for which the angle of deviation is 90°.
Explain: ‘How is a rainbow formed’?
Answer the following question in detail.
State the conditions under which a rainbow can be seen.
Answer the following question in detail.
Is it possible to see primary and secondary rainbow simultaneously? Under what conditions?
Pick the wrong answer in the context with rainbow.
A plano-convex lens is made of material having refractive index 1.5. The radius of curvature of curved surface is 40 cm. The focal length of the lens is ____________ cm.
Explain the formation of primary and secondary rainbow.
| Case study: Mirage in deserts |
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To a distant observer, the light appears to be coming from somewhere below the ground. The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object. Such inverted images of distant tall objects cause an optical illusion to the observer. This phenomenon is called mirage. This type of mirage is especially common in hot deserts. Based on the above facts, answer the following question : |
In an optical fibre, if n1 and n2 are the refractive indices of the core and cladding, then which among the following, would be a correct equation?
| Case study: Mirage in deserts |
|
|
To a distant observer, the light appears to be coming from somewhere below the ground. The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object. Such inverted images of distant tall objects cause an optical illusion to the observer. This phenomenon is called mirage. This type of mirage is especially common in hot deserts. Based on the above facts, answer the following question: |
A diamond is immersed in such a liquid which has its refractive index with respect to air as greater than the refractive index of water with respect to air. Then the critical angle of diamond-liquid interface as compared to critical angle of diamond-water interface will
| Case study: Mirage in deserts |
|
|
To a distant observer, the light appears to be coming from somewhere below the ground. The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object. Such inverted images of distant tall objects cause an optical illusion to the observer. This phenomenon is called mirage. This type of mirage is especially common in hot deserts. Based on the above facts, answer the following question: |
The following figure shows a cross-section of a ‘light pipe’ made of a glass fiber of refractive index 1.68. The outer covering of the pipe is made of a material of refractive index 1.44. What is the range of the angles of the incident rays with the axis of the pipe for the following phenomena to occur.
A short pulse of white light is incident from air to a glass slab at normal incidence. After travelling through the slab, the first colour to emerge is ______.
