Optics Problem #0097

We have to show that in the Newton’s rings experiment that (a) the difference in the radius between adjacent rings (maxima) is given by

assuming , and (b) that the area between the adjacent rings (maxima) is given by

assuming . We note that this area is independent of m.

Solution: Click For PDF Version
(a)

We recall from the preceding problem that the radius of the mth bright Newton’s ring is given by the relation

Therefore,

Assuming that

and using the approximation

we find that

(b)

From the above, we note that the area between the adjacent bright rings will be

which is independent of m.