Advertisements
Advertisements
Question
Define a wavefront. Using 'Huygens' principle, draw the shape of a refracted wavefront, when a plane wave is incident on a convex lens.
Advertisements
Solution
The locus of points, which oscillate in phase is called a wavefront; thus a wavefront is defined as a surface of constant phase.
In the given figure we consider a plane wave incident on a thin convex lens, the emerging wavefront is spherical and converges to point F which is known as the focus.
APPEARS IN
RELATED QUESTIONS
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?
Light emerging out of a convex lens when a point source is placed at its focus.
You have learnt in the text how Huygens’ principle leads to the laws of reflection and refraction. Use the same principle to deduce directly that a point object placed in front of a plane mirror produces a virtual image whose distance from the mirror is equal to the object distance from the mirror.
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.
A plane wave front AB propagating from denser medium (1) into a rarer medium (2) is incident on the surface P1P2 separating the two media as shown in fig.
Using Huygen’s principle, draw the secondary wavelets and obtain the refracted wave front in the diagram.
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.
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.
Represent diagrammatically how the incident planar wavefronts of wavelength λ pass through an aperture of size d, when d is approximately equal to λ.
Represent diagrammatically how the incident planar wavefronts of wavelength λ pass through an aperture of size d, when d is approximately equal to λ.
