Advertisements
Advertisements
प्रश्न
State Huygens’s principle. Show, with the help of a suitable diagram, how this principle is used to obtain the diffraction pattern by a single slit.
Draw a plot of intensity distribution and explain clearly why the secondary maxima becomes weaker with increasing order (n) of the secondary maxima.
Advertisements
उत्तर
Huygen’s principle states that
-
Each point on a wave front behaves as a source of secondary wavelets
-
The secondary wavelets travel with the speed of light in that medium
-
The position of new wave front at a later time can be found out by drawing a common tangent to all these secondary wavelets
Intensity distribution of single slit distribution
For the first secondary maxima (n = 1), only one-third of the slit contributes to its intensity.
Secondly, for n = 2, only one-fifth of the slit contributes to the intensity.
Therefore, with increasing n, the intensity decreases.
APPEARS IN
संबंधित प्रश्न
What is the shape of the wavefront in the following case?
Light diverging from a point source.
What is the shape of the wavefront in the following case?
Light emerging out of a convex lens when a point source is placed at its focus.
Using Huygens’ principle, verify the laws of reflection at a plane surface.
With what type of source of light are cylindrical wave fronts associated?
Answer the following question.
Define the term wavefront. Using Huygen's wave theory, verify the law of reflection.
The inverse square law of intensity is valid for a
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.
Consider a point at the focal point of a convergent lens. Another convergent lens of short focal length is placed on the other side. What is the nature of the wavefronts emerging from the final image?
Two light beams of intensities in the ratio of 9 : 4 are allowed to interfere. The ratio of the intensity of maxima and minima ______.
What type of wavefronts are associated with a point source of light?
