Use the figure for the next two questions.
-The interference pattern is from a convex lens placed on a flat reflecting surface using a monochromatic light of wavelength $\lambda$ = 550 nm.The distance between the lens and the flat surface at position A is
A)275 nm
B)550 nm
C)687.5 nm
D)825 nm
E)962.5 nm

Question

Use the figure for the next two questions. 
-The interference pattern is from a convex lens placed on a flat reflecting surface using a monochromatic light of wavelength $\lambda$ = 550 nm.The distance between the lens and the flat surface at position A is
A)275 nm 
B)550 nm 
C)687.5 nm 
D)825 nm 
E)962.5 nm

Quizplus · Accepted Answer

The interference pattern observed is due to the formation of Newton's rings, which occur when a convex lens is placed on a flat reflecting surface and illuminated with monochromatic light. The distance between the lens and the flat surface at a point of dark fringe (destructive interference) can be calculated using the formula for the radius of the nth dark ring: $r_n = \sqrt{n\lambda R}$, where $R$ is the radius of curvature of the lens, $\lambda$ is the wavelength of the light used, and $n$ is the ring number (starting from 0 for the first dark ring). However, without needing to delve into specifics about the ring number or the radius of curvature, the key insight here is that the distance between the lens and the surface at a point of interference is half the wavelength of the light in the medium between the lens and the surface, because the path difference for the first minimum (dark fringe) is half the wavelength. Since the wavelength given is 550 nm, the distance for the first minimum would be half of that, which is 275 nm. However, the question seems to be looking for a different interpretation, possibly involving the full wavelength as the path difference for constructive interference, but without additional context or a clear indication of the specific interference order or type (constructive vs. destructive), the direct application of the given wavelength leads to confusion. Given the options and the typical interpretation of interference patterns in such a setup, none directly apply to the standard calculations for Newton's rings or typical interference patterns without additional context. Thus, the response assumes a potential misunderstanding or misinterpretation of the question's intent based on standard physics principles.

Use the Figure for the Next Two Questions λ\lambdaλ = 550 NmThe Distance Between the Lens and the Flat Surface at Interference

Use the Figure for the Next Two Questions $\lambda$ = 550 NmThe Distance Between the Lens and the Flat Surface at Interference