Problem

Figure shows two coherent sources

S_1

and

S_2

vibrating in same phase.

AB

is an irregular wire lying at a far distance from the sources

S_1

and

S_2

. Let

\frac{\lambda}{d} = 10^{-3}

\angle BOA = 0.12^\circ

. How many bright spots will be seen on the wire, including points

A

and

B