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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
Name the phenomenon responsible for it.
Show with the help of a diagram, how unpolarised light from Sun gets linearly polarised by scattering.
In the meterbridge experimental set up, shown in the figure, the null point ‘D’ is obtained at a distance of 40 cm from end A of the meterbridge wire. If a resistance of 10Ω is connected in series with R1, null point is obtained at AD = 60 cm. Calculate the values of R1 and R2.
The image formed by a concave mirror
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 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.
A container contains water up to a height of 20 cm and there is a point source at the centre of the bottom of the container. A rubber ring of radius r floats centrally on the water. The ceiling of the room is 2.0 m above the water surface.
- Find the radius of the shadow of the ring formed on the ceiling if r = 15 cm.
- Find the maximum value of r for which the shadow of the ring is formed on the ceiling. Refractive index of water = `4/3`.
A biconvex thick lens is constructed with glass (μ = 1.50). Each of the surfaces has a radius of 10 cm and the thickness at the middle is 5 cm. Locate the image of an object placed far away from the lens.
Fill in the blank and rewrite the completed statement:
Very fine particles mainly scatter ______ light.
Explain: ‘How is a rainbow formed’?
Answer the following question in detail.
Explain the formation of a secondary rainbow. For which angular range with the horizontal is it visible?
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.
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 : |
A diver at a depth 12 m inside water `(a_(µω) = 4/3)` sees the sky in a cone of semi-vertical angle
Between the primary and secondary rainbows, there is a dark band known as Alexandar’s dark band. This is because ______.
- light scattered into this region interfere destructively.
- there is no light scattered into this region.
- light is absorbed in this region.
- angle made at the eye by the scattered rays with respect to the incident light of the sun lies between approximately 42° and 50°.
