Two rectangular optically flat plates (n = 1.52) are in contact along one end and are separated along the other end by a 1.90 m thick spacer (Fig.

Two rectangular optically flat plates (n = 1.52) are in contact along one end and are separated along the other end by a 1.90 µm thick spacer (Fig. 24.22). The top plate is illuminated by monochromatic light of wavelength 549.1 nm. Calculate the number of dark parallel bands crossing the top plate (including the dark band at zero thickness along the edge of contact between the two plates).