Question

Wave normal are drawn to a wavefront at various points. It is found that they are parallel in a vertical plane and diverging in a horizontal plane. Then the source of the wavefront is

1) a point source                  2) a narrow horizontal slit

3) a narrow vertical slit        4) a tuning fork

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Answer 1

The source of the wavefront is a point source

Explanation:

Wave normal are drawn to a wavefront at various points. It is found that they are parallel in a vertical plane and diverging in a horizontal plane. Then the source of the wavefront is a point source.

• In case of a light diverging from a point source the shape of the wave front is spherical.
• In case of a light emanating from a convex lens when a point source is positioned at its center, the form of the wavefront is a parallel grid.

Option 1 is the answer.