Advertisements
Advertisements
Question
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.
Options
a and b
a and c
b and c
c and d
Advertisements
Solution
a and b
Explanation:
| Type of wavefront | Intensity | Amplitude |
Spherical |
`I oo 1/r^2` | `A oo 1/r` |
Cylindrical |
`I oo 1/r` | `A oo 1/sqrt(r)` |
Plane |
`I oo 1/r^0` | `A oo r^0` |
Due to the point source light propagates in all directions symmetrically and hence, wavefront will be spherical as shown in the diagram.
As intensity of the source will be `I oo 1/r^2`
Where r is radius of the wavefront at any time.
Hence the intensity decreases in proportion to the distance squared.
APPEARS IN
RELATED QUESTIONS
On the basis of Huygens' wave theory of light prove that velocity of light in a rarer medium is greater than velocity of light in a denser medium.
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.
Use Huygens' principle to verify the laws of refraction.
Using Huygens’ principle, verify the laws of reflection at a plane surface.
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
Light waves travel in vacuum along the X-axis. Which of the following may represent the wave fronts?
Derive the law of reflection using Huygen’s Wave Theory.
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.
Relation between ray and wavefront is ______.
What is the geometrical shape of the wavefront for:
- Light diverging from a point source?
- The pattern of wavefront of the light from a distant star intercepted by earth?
The inverse square law of intensity is valid for a
Huygen's conception of secondary waves ______.
Figure shows a standard two slit arrangement with slits S1, S2, P1, P2 are the two minima points on either side of P (Figure). At P2 on the screen, there is a hole and behind P2 is a second 2-slit arrangement with slits S3, S4 and a second screen behind them.
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 source infinity?
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.
