Two microscope slides made of glass are illuminated by monochromatic (λ=589nmλ=589nm) light incident perpendicular to the surface. The top slide touches the bottom slide at one end and rests on a thin copper wire at the other end, forming a wedge of air. Dimensions are not to scale. The wire diameter and the thickness of the gap should be very small compared to the thickness of the glass.. If 104 bright fringes appear between the point where the glass slides contact each other and where they contact the wire, what is the minimum diameter D of the wire in micrometers.

Two microscope slides made of glass are illuminated by monochromatic (λ=589nmλ=589nm) light incident perpendicular to the surface. The top slide touches the bottom slide at one end and rests on a thin copper wire at the other end, forming a wedge of air. Dimensions are not to scale. The wire diameter and the thickness of the gap should be very small compared to the thickness of the glass.. If 104 bright fringes appear between the point where the glass slides contact each other and where they contact the wire, what is the minimum diameter D of the wire in micrometers.