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प्रश्न
What is a principle of reversibility?
उत्तर
The principle of reversibility states that light will follow exactly the same path if its direction of travel is reversed.
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संबंधित प्रश्न
A tank is filled with water to a height of 12.5 cm. The apparent depth of a needle lying at the bottom of the tank is measured by a microscope to be 9.4 cm. What is the refractive index of water? If water is replaced by a liquid of refractive index 1.63 up to the same height, by what distance would the microscope have to be moved to focus on the needle again?
For the same value of angle of incidence, the angles of refraction in three media A, B and C are 15°, 25° and 35° respectively. In which medium would the velocity of light be minimum?
Consider the situation in figure. The bottom of the pot is a reflecting plane mirror, S is a small fish and T is a human eye. Refractive index of water is μ. (a) At what distance(s) from itself will the fish see the image(s) of the eye? (b) At what distance(s) from itself will the eye see the image(s) of the fish.
A point ‘O’ marked on the surface of a glass sphere of diameter 20 cm is viewed through glass from the position directly opposite to the point O. If the refractive index of the glass is 1.5, find the position of the image formed. Also, draw the ray diagram for the formation of the image.
Obtain the equation for apparent depth.
A light travels through water in the beaker. The height of water column is 'h'. Refractive index of water is 'μw'. If c is velocity of light in air, the time taken by light to travel through water will ______.
When a light ray is incident on a prism at an angle of 45°, the minimum deviation is obtained. If refractive index of material of prism is `sqrt2`, then angle of prism will be ______.
`sin pi/4=1/sqrt2, sin30^circ=cos60^circ=1/2`
A concave mirror of focal length 'f1' is placed at a distance 'd' from a convex lens of focal length 'f2'. A parallel beam of light coming from infinity parallel to principal axis falls on the convex lens and then after refraction falls on the concave mirror. If it is to retrace the path, the distance 'd' should be ______.
A beam of light travels from air into a medium. Its speed and wavelength in the medium are 1.5 × 108 ms-1 and 230 nm respectively. The wavelength of light in the air will be ______.
