Tag: wave optics

Questions Related to wave optics

Choose the Correct answer from alternative given.
The phenomena which is not explained by Huygen's construction of wavefront.

  1. reflection

  2. diffraction

  3. refraction

  4. origin of spectra


Correct Option: D
Explanation:

The Huygen's construction of wavefront does not explain the phenomena of spectra.

Choose the Correct answer from alternative given.
Wavefront is the locus of all points, where the particles of the medium vibrate with the same

  1. phase

  2. amplitude

  3. frequency

  4. period


Correct Option: A
Explanation:

Wavefront is the locus of all points, where the particles of the medium vibrate with the same phase.

Choose the Correct answer from alternative given.
The idea of secondary wavelets for the propagation of a wave was first given by:

  1. Newton

  2. Huygens

  3. Maxwell

  4. Fresnel


Correct Option: B
Explanation:

According to the Huygens theory, all the points on a  wavefront act as source for a secondary wavefront or a wavelet which spread outward from the point and move at the speed of light.

The phenomena which is not explained by Huygen's construction of the wavefront

  1. reflection

  2. diffraction

  3. refraction

  4. origin of spectra


Correct Option: D
Explanation:

The Huygen's construction of wavefront does not explain the phenomena of origin of spectra.

Wavefront is the locus of all points, where the particles of the medium vibrate with the same.

  1. phase

  2. amplitude

  3. frequency

  4. period


Correct Option: A
Explanation:

Wavefront is the locus of all points, where the particles of the medium vibrate with the same phase

The wavelength of characteristic $X \text { -ray } K _ { \alpha }$ a line emitted by hydrogen like atom is $0.32 \mathrm { A } ^{ \circ }$. The wavelength of $K _ { \beta }$ line emitted by the same element is 

  1. $0.21 { \mathrm { A } }$

  2. $0.27 \mathrm { A }$

  3. $0.33 \mathrm { A }$

  4. $0.40 \hat { \mathrm { A } }$


Correct Option: A

A transverse wave travelling in a denser medium is reflected from a rarer medium. Then, 

  1. an incident crest is reflected as a crest

  2. an incident crest is reflected as a trough

  3. there is a phase change of $2\pi$ rad

  4. there is a phase change of $\pi/2$ rad


Correct Option: A

The radius of a wavefront as the waves propagate

  1. decreases

  2. increases

  3. becomes zero

  4. sometimes decreases and sometimes increases.


Correct Option: B
Explanation:

As the waves propagates, it goes on creating secondary sources of light, resulting in increase in its radius.

Huygens principle of secondary waves

  1. allow us to find the focal length of a thick convex lens.

  2. give us the magnifying power of the microscope.

  3. is a geometrical method to find, the position of a wave front.

  4. is used to determine the velocity of light.


Correct Option: C
Explanation:

Huygens's Principle states that every point on a wavefront is a source of secondary wavelets, which spread forward at the same speed.

Thus is enables to find the position of wavefront.

The wave front due to a source situated at infinity is :

  1. spherical

  2. cylindrical

  3. planar

  4. none of these


Correct Option: C
Explanation:
  • when you considered it a large distance and measuring justice Mall section of it then it can be considered to be plane wavefront source at Infinity 
  • example the one coming from sun to earth surface is considered to be plain VU friend from light diverging from a point source will be spherical
  • So, the wave front due to a source situated at infinity is planar
  • Option  C is the right answer