Assertion : When a tiny circular obstacle is | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) When light from a distant source encounters a small circular obstacle,the light waves diffract around the edges of the obstacle.According to the H

Vedclass · Accepted Answer

If the Assertion is correct but Reason is incorrect.

Vedclass · Answer

(C) When light from a distant source encounters a small circular obstacle,the light waves diffract around the edges of the obstacle.According to the Huygens-Fresnel principle,every point on the edge of the obstacle acts as a source of secondary wavelets.These secondary wavelets travel to the centre of the geometric shadow and arrive in phase with each other.Because they arrive in phase,they undergo constructive interference,resulting in a bright spot at the centre of the shadow,which is known as the Poisson spot or Arago spot.Therefore,the Assertion is correct,but the Reason is incorrect because constructive interference,not destructive interference,occurs at the centre.

Assertion : When a tiny circular obstacle is placed in the path of light from some distance,a bright spot is seen at the centre of the shadow of the obstacle.
Reason : Destructive interference occurs at the centre of the shadow.

Similar Questions

On which factor does the number of interference fringes in a given width of a diffraction peak depend?

When a compact disc $(CD)$ is illuminated by a small source of white light,coloured bands are observed. This is due to

Two slits are made $1 \; mm$ apart and the screen is placed $1 \; m$ away. What should the width of each slit be to obtain $10$ maxima of the double-slit pattern within the central maximum of the single-slit pattern (in $; mm$)? Blue-green light of wavelength $500 \; nm$ is used.

The diffraction fringes obtained from a single slit are.....

In the diffraction pattern of a single slit,the width of the secondary maxima compared to the central maximum is:

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Assertion : When a tiny circular obstacle is placed in the path of light from some distance,a bright spot is seen at the centre of the shadow of the obstacle.Reason : Destructive interference occurs at the centre of the shadow.