A convex lens is placed on a flat glass plate and illuminated from above with monochromatic red light. When viewed from above, concentric bands of red and dark are observed. What does one observe at the exact center of the lens where the lens and the glass plate are in direct contact?
a. a bright spot that is some color other than red
b. a dark spot
c. a bright red spot
d. a rainbow of color
This is an example of newtons rings. The circular interference fringes appear, associated with the variable thickness air film between the lens and the plate. ...
This solution is provided in 130 words. It discusses Newton's rings and calculates maximum intensity to solve the problem.