Optics Question 878
Question: Two rectangular glass plates are in contact at one edge while the other edges are separated by a space of some suitable thickness so as to form a low angle wedge. The spacer is placed parallel to the line of contact and is at a distance of 10 cm from it. When viewed normally in light of wavelength 5500 A, a series of evenly spaced dark bands 0.5 mm apart are seen. The thickness of the spacer is :
Options:
A) 0.0425cm
B) 0.0036cm
C) 0.0055cm
D) 0.0254cm
Show Answer
Answer:
Correct Answer: C
Solution:
[c] $ \beta =\frac{\lambda }{2\mu \alpha }=\frac{\lambda }{2\mu ( \frac{t}{x} )} $
$ =\frac{\lambda x}{2\mu t} $ or $ t=\frac{\lambda x}{2\beta \mu } $
