Tag: wave optics

Questions Related to wave optics

In the case of parallel beam,

  1. intensity gradually increases

  2. intensity gradually decreases

  3. intensity remains constant

  4. None of these


Correct Option: D

Huygen's theory of light

  1. explain reflection and refraction of light

  2. explain scattering of light

  3. explain interference of light, diffraction of light

  4. None of the above


Correct Option: C

According to huygen's theory of secondary waves,following can be explained-

  1. Propagation of light in medium

  2. Reflection of light

  3. Refrection of light

  4. All of the above


Correct Option: A,B

Huygen's theory of secondary waves can be used of find-

  1. Velocity of light

  2. The wavelength of light

  3. Wave front geometrically

  4. Magnifying power of microscope


Correct Option: B

Huygen's theory of secondary waves can be used to find-

  1. Velocity of light

  2. The wavelength of light

  3. Wave front geometrically

  4. Magnifying power of microscope.


Correct Option: B

Coherent sources can be obtained:

  1. only by division of wave front

  2. only by division of amplitude

  3. both by division of amplitude and wave front

  4. none of the above


Correct Option: C

The wave theory in its original form was first postulated by 

  1. Issac Newton

  2. Thomas Young

  3. Christian Huygens

  4. Augustine Jean Fresnel


Correct Option: C
Explanation:

Christian Huygens postulated wave theory.

Assertion  $(A):$  Microwaves are better carries of signals than optical waves
Reason  $(R):$  Microwaves move faster than optical waves

  1. Both $A$ and $R$ are true and $R$ is correct explanation of $A$

  2. Both $A$ and $R$ are true and $R$ is not the correct explanation of $A$

  3. $A$ is true but $R$ is false

  4. $A$ is false but $R$ is true


Correct Option: D
Explanation:
A frequency of an optical wave is more than the microwave so optical waves are better canes of the signal, therefore, A is false. In medium (other than vacuum) speed of 0 microwaves 1A greater than optical wave hence R 1A true.
Ans. (D)

A wave pulse traveling on a two piece string, gets partially reflected and partially transmitted at the junction. The reflected wave is inverted in shape as compared to incident one. If the incident wave has wavelength  $\lambda$  and transmitted wave has  $\lambda ',$  then

  1. $\lambda '> \lambda$

  2. $\lambda' = \lambda$

  3. $\lambda' < \lambda$

  4. none


Correct Option: C
Explanation:

Reflected wave is inverted hence second medium is dir sec with respect to first medium. $\lambda ' < \lambda $

$\frac{{\lambda '}}{t} < \frac{\lambda }{t} \Rightarrow \lambda ' < \lambda $
Ans. (C)

The wave front due to a point source at a finite distance from the source is -

  1. Spherical

  2. Cylindrical

  3. Plane

  4. Circular


Correct Option: C