The frequencies of sources A and B as shown in figure are same. The nature of interference at points P, Q and R will be if \(AB=\frac{\lambda}{2}\) and the two sources are in same phase
1
constructive a P, destructive at Q and R
2
constructive at P and R, destructive at Q
3
constructive at P and Q, destructive at R
4
constructive at R, destructive at P and Q