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प्रश्न
Consider a plane wave front incident on a thin convex lens. Draw a proper diagram to show how the incident wave front traverses through the lens and after refraction focusses on the focal point of the lens, giving the shape of the emergent wave front.
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उत्तर
The new position of the wavefront at any instant (called secondary wave front) is the envelope of the secondary wavelets at that instant.
Incident wave front traversing through the lens and after refraction focusing on the focal point of the lens is shown in the figure below.
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संबंधित प्रश्न
Using Huygens's construction of secondary wavelets explain how a diffraction pattern is obtained on a screen due to a narrow slit on which a monochromatic beam of light is incident normally.
What is the shape of the wavefront in the following case?
The portion of the wavefront of light from a distant star was intercepted by the Earth.
When the width of the slit is made double the original width, how would this affect the size and intensity of the central diffraction band?
Huygens' principle of secondary wavelets may be used to
(a) find the velocity of light in vacuum
(b) explain the particle behaviour of light
(c) find the new position of a wavefront
(d) explain Snell's Law
Answer the following question.
Define the term wavefront. Using Huygen's wave theory, verify the law of reflection.
Answer the following question briefly and to the point:
What is the phase difference between any two points lying on the same wavefront?
Wavefront means
For light diverging from a point source ______.
- the wavefront is spherical.
- the intensity decreases in proportion to the distance squared.
- the wavefront is parabolic.
- the intensity at the wavefront does not depend on the distance.
Two light beams of intensities in the ratio of 9 : 4 are allowed to interfere. The ratio of the intensity of maxima and minima ______.
Using Huygen's wave theory of light, show that the angle of incidence is equal to the angle of reflection. Draw a neat and labelled diagram.
