In an experiment used to show Newton’s rings, a plano-convex lens is placed on a flat glass plate, as in Fig. 40-5. When the lens is illuminated from directly above, a top-side viewer sees a series of bright and dark rings centered on the contact point, which is dark. Find the air-gap thickness at 

(a) The third dark ring and 

(b) The second bright ring. 

Assume 500-nm light is being used.

Transcribed Image Text:

Fig. 40-5