Question is based on the following paragraph.
An initially parallel cylindrical beam travels in a medium of refractive index are positive constants and is the intensity of the light beam. The intensity of the beam is decreasing with increasing radius.
Question: The initial shape of the wavefront of the beam is
planar
convex
concave
convex near the axis and concave near the periphery
As we learnt in
Refractive index -
- wherein
speed of light in vacuum.
speed of light in medium.
For a parallel cylindrical beam, wavelength will be planar.
Correct option is 1.
Option 1)
planar
This is the correct option.
Option 2)
convex
This is an incorrect option.
Option 3)
concave
This is an incorrect option.
Option 4)
convex near the axis and concave near the periphery
This is an incorrect option.
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