Each of the diagrams at right shows all the nodal lines (dashed) and all

the lines of maximum constructive interference (solid) due to two

point sources. The wavelength, %u03BB, is the same in all three cases; the

source separation is different. The sources, which are not shown, lie

along a horizontal line.

a. Label each nodal line and line of maximum constructive

interference in the shaded region with the appropriate value of %u2206r

(in terms of %u03BB). (%u2206r is the difference in distances to the sources.)

b. For each case, determine the source separation (in terms of %u03BB).

For any case(s) for which it is not possible to determine the source

separation exactly, determine the source separation as closely as

you can, i.e., give the smallest range into which the source

separation must fall.

c. Explain how you determined the source separations.

Case X Case Y Case X Case Y