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प्रश्न
What is normal focusing?
उत्तर
The image is formed at infinity. In this position, the eye is most relaxed to view the image.
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संबंधित प्रश्न
What is a Polaroid?
Show, with the help of a diagram, how unpolarised sunlight gets polarised due to scattering.
Two polaroids P1 and P2 are placed with their pass axes perpendicular to each other. An unpolarised light of intensity I0 is incident on P1. A third polaroid P3 is kept in between P1 and P2 such that its pass axis makes an angle of 30° with that of P1. Determine the intensity of light transmitted through P1, P2 and P3
Show, via a suitable diagram, how unpolarised light can be polarised by reflection.
The refractive indices of water for red and violet colours are 1.325 and 1.334 respectively.
Find the difference between the velocities of rays for these two colours in water. (c = 3 × 108 m/s)
What is the value of refractive index of a medium of polarising angle 60°?
The glass plate of refractive index 1.732 is to be used as a polarizer, its polarising angle is _______.
A ray of light is incident on a transparent medium at a polarizing angle. What is the angle between the reflected ray and the refracted ray?
A ray of ordinary light is travelling in air. It is incident on air glass pair at a polarising angle of 56°. Find the angle of refraction in glass.
Explain how an unpolarised light gets polarised when incident on the interface separating the two transparent media.
Discuss polarisation by selective absorption.
What is a analyser?
What is plane polarised light?
What is partially polarised light?
State Brewster’s law.
What is double refraction?
To ensure almost 100 per cent transmissivity, photographic lenses are often coated with a thin layer of dielectric material. The refractive index of this material is intermediated between that of air and glass (which makes the optical element of the lens). A typically used dielectric film is MgF2 (n = 1.38). What should the thickness of the film be so that at the center of the visible spectrum (5500 Å) there is maximum transmission.
An unpolarized light beam is incident on the polarizer of a polarization experiment and the intensity of light beam emerging from the analyzer is measured as 100 Lumens. Now, if the analyzer is rotated around the horizontal axis (direction of light) by 30° in clockwise direction, the intensity of emerging light will be ______ Lumens.
