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प्रश्न
Answer the following question in detail.
Is it possible to see primary and secondary rainbow simultaneously? Under what conditions?
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उत्तर
Yes, it is possible to see primary and secondary rainbows simultaneously. This can occur when the centres of both the rainbows coincide.
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संबंधित प्रश्न
Give a scientific reason:
Danger signal lights are red in colour.
Name the phenomenon responsible for it.
Why does unpolarised light from a source show a variation in intensity when viewed through a polaroid which is rotated?
Draw the intensity distribution for the fringes produced in interference ?
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 thin lens is made with a material having refractive index
\[\mu = 1 \cdot 5\]. Both the side are convex. It is dipped in water \[\mu = 1 \cdot 33\]. 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 concave mirror forms an image of 20 cm high object on a screen placed 5.0 m away from the mirror. The height of the image is 50 cm. Find the focal length of the mirror and the distance between the mirror and the object.
A concave mirror has a focal length of 20 cm. Find the position or positions of an object for which the image-size is double of the object-size.
A 1 cm object is placed perpendicular to the principal axis of a convex mirror of focal length 7.5 cm. Find its distance from the mirror if the image formed is 0.6 cm in size.
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.
Locate the image of the point P as seen by the eye in the figure.
An optical fibre (μ = 1.72) is surrounded by a glass coating (μ = 1.50). Find the critical angle for total internal reflection at the fibre-glass interface.
Light is incident from glass (μ = 1.50) to water (μ = 1.33). Find the range of the angle of deviation for which there are two angles of incidence.
Light falls from glass (μ = 1.5) to air. Find the angle of incidence for which the angle of deviation is 90°.
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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.
Explain the formation of a secondary rainbow. For which angular range with the horizontal is it visible?
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Explain the formation of primary and secondary rainbow.
A parallel beam of light of wavelength 5890 Å falls normally on a slit of width 0.2 mm. Find the distance between the first minima on the two sides of the central maximum of the diffraction pattern observed on a screen placed in the focal plane of a convex lens of focal length 50 cm. The lens is placed quite close to the slit.
| 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: |
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 passenger in an aeroplane shall ______.
