Assertion : When a tiny circular obstacle is | vedclass

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(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

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If the Assertion is correct but Reason is incorrect.

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(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.

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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.