a tiny circular obstacle is placed in the path of light from distant source,a bright spot seen at the centre.?

Question

I want to know why? For class 12 basis.

Answer 1

This only happens because of the wave properties of light. It works with sound and water ripples as well. The fancy name for this is "diffraction", which studies the complex equations describing how waves self-interfere as they get past obstacles. See wiki, 1st link.

The case of diffraction around a circular obstacle is called Arago's spot, or Poisson's spot. See wiki, 2nd link.

The case of diffraction through a circular opening is called Airy diffraction. See wiki, 3rd link.

Answer 2

This happens due to the phenomenon of Diffraction.
which states that when a tiny obstacle is placed in the path of light, it deviates slightly from its main path and thereby leaving a central bright fringe, and other fringes of decreasing intensities and in the end the intensity is very low and the pattern is stopped. This pattern is seen on both sides of the obstacle and thus you see a bright spot of maximum intensity in the centre of the pattern.

Answer 3

We know that light travels in the form of small particals known as "Photons".

Due to placing a partical in the path of a light ray the photons will strike the small partical and diverge their way, because they can not pass through the particle and bright shadow is formed at the screen.

These photons are emitted from the light in the form of small packets.

Answer 4

the answer to this problem requires a diagram, u will have to contact me in order to understand