A 35-Cm-Long Microscope Glass Slide Has One Edge in Contact with with a Flat

Multiple Choice

A 3.5-cm-long microscope glass slide has one edge in contact with a flat plane of glass,while the other edge is slightly raised due to the insertion of a thin piece of paper.Sodium light of wavelength 589 nm is normally incident on the glass from above and interference fringes are observed by reflection with a regular spacing of 0.22 mm.Calculate the thickness of the piece of paper.

A) 9.4 $\times$ 10^-5 m
B) 5.5 $\times$ 10^-5 m
C) 2.4 $\times$ 10^-5 m
D) 4.7 $\times$ 10^-5 m
E) None of these is correct.