\(d\,\,\sin \,\,\theta \,\, = \,\,\left( {2\,\, \times \,\,\frac{1}{2}} \right)\,\,\lambda \,\, = \,\,\frac{{5\lambda }}{2}\,\,\,......\left( 1 \right)\)

હવે બીજા અધિકતમ ની,

રેખિયા પહોળાઈ \( = \,\,d\,\,\theta \,\, = \,\,d\,\,\frac{x}{{D\,\,\left( { = \,\,{f}} \right)}}\,\, = \,\,\frac{{dx}}{{f}}\,\,\,..........\left( 2 \right)\)

\((\because \,\theta \) અતિ નાનો હોવાથી \( \sin \,\,\theta  = \theta \,rad\) અને સમીકરણ \((1)\) વાપરતા )

\(\therefore \,\,\frac{{dx}}{{f}}\,\, = \,\,\frac{{5\lambda }}{2}\,\,\,\,\therefore \,\,2x\,\, = \,\,\frac{{5\lambda {f}}}{d}\,\, = \,\,\frac{{5\,\, \times \,\,\left( {6\,\, \times \,\,{{10}^{ - 7}}} \right)\,\, \times \,\,\left( {0.8} \right)}}{{4\,\, \times \,\,{{10}^{ - 4}}}}\)

\(\, = \,\,6\,\, \times \,\,{10^{ - 3}}\,\,m\, = \,\,6\,\,mm\)