Question

n an experiment, white light is shone vertically down upon a convex spherical lens that is resting (curved side down) on a flat piece of glass. which of the following statements correctly explain why there is there a dark ring at the centre of the resulting interference pattern? note: more than one of the statements may be correct. to get full marks all correct and no incorrect statements must be selected. question 4select all that apply: destructive interference of two reflected rays occurs cross out destructive interference of the reflected ray and the refracted ray occurs cross out constructive interference of two reflected rays occurs cross out the thickness of the air wedge is equal to one-half wavelength at that location cross out the thickness of the air wedge is negligible at that location cross out there is a 180 degree phase difference (due to reflection) between the two reflected rays g

Answer 1

The dark ring in an interference pattern created by white light passing through a convex lens on glass is due to destructive interference, where the air wedge thickness is negligible or equal to half the wavelength of light, and a 180-degree phase difference occurs between the two reflected rays.

Step-by-step explanation:

The appearance of a dark ring at the centre of an interference pattern when white light is shone on a convex spherical lens resting on flat glass can be explained by thin-film interference. Specifically, destructive interference of two reflected rays can occur at this spot if the rays have a 180-degree phase difference due to one ray reflecting off a higher refractive index material than the other.

Moreover, the dark ring can also indicate the point at which the thickness of the air wedge between the lens and the glass is negligible, or equivalently, an area where the air film's thickness is equal to half the wavelength of light, leading to destructive interference.