Question

Plane microwaves are incidnet on a long slit having a width of 5.0 cm. Calculate the wavelength of the microwaves if the first diffraction m8inimum is formed at $\theta ={30}^{\circ }$

Answer 1

For first minimum diffraction,$b\sin \varphi =\lambda$
Here, $\theta ={30}^{\circ },b=5cm\therefore \lambda =5\times \sin {30}^{\circ }=\frac{5}{2}=2.5$