Wave Optics

In a diffraction pattern due to single slit of width '\(a\)', the first minimum is observed at an angle of \(30^{\circ}\) when the light of wavelength \(5400 \mathop A\limits^o\) is incident on the slit. The first secondary maximum is observed at an angle of \(\left(\sin 30^{\circ}=\frac{1}{2}\right)\)