\(d \sin \theta=\lambda\)

\(\sin \theta=\frac{\lambda}{d}<1\)

\(\therefore  \lambda < d\)

\(\frac{h}{{\left| {{p_y}} \right|}} < d\)      \(\left[ {\because \lambda  = \frac{h}{{\left| {{p_y}} \right|}}} \right]\)

\(\therefore \quad h<\left|p_{y}\right| d\)