Question
Physics Question on Youngs double slit experiment
A thin slice is cut out of a glass cylinder along a plane parallel to its axis. The slice is placed on a flat plate as shown. The observed interference fringes from this combination shall be
A
straight
B
circular
C
equally spaced
D
having fringe spacing which increases as we go outwards
Answer
straight
Explanation
Solution
Locus of equal path difference are the lines running parallel
to the axis of the cylinder. Hence, straight fringes are
obtained.
NOTE Circular rings (also called Newton's rings) are observed in
interference pattern when a plano-convex lens of large focal length is
placed with its convex surface in contact with a plane glass plate
because locus of equal path difference in this case is a circle.