The interference pattern is from a lens placed on a flat reflecting surface illuminated using a monochromatic light from above. From the pattern one can conclude that the lens
A) is more curved on the left and right sides compared to top and bottom.
B) is more curved on the top and bottom compared to the left and right sides.
C) has a spherical surface.
D) has a concave surface.
E) is none of the above.

Question

The interference pattern is from a lens placed on a flat reflecting surface illuminated using a monochromatic light from above. From the pattern one can conclude that the lens
A) is more curved on the left and right sides compared to top and bottom. 
B) is more curved on the top and bottom compared to the left and right sides. 
C) has a spherical surface. 
D) has a concave surface. 
E) is none of the above.

Quizplus · Accepted Answer

The interference pattern shows that the surface of the lens is more curved on the top and bottom compared to the left and right sides. This is indicated by the horizontal fringes being more closely spaced than the vertical fringes, which suggests that the surface is shaped like a cylindrical lens. Since the fringes are straight, it can be concluded that the surface is not spherical or concave.

The Interference Pattern Is from a Lens Placed on a Flat