Wave Optics Question 2

Question 2 - 2024 (01 Feb Shift 2)

A microwave of wavelength $2.0 cm$ falls normally on a slit of width $4.0 cm$. The angular spread of the central maxima of the diffraction pattern obtained on a screen $1.5 m$ away from the slit, will be:

(1) $30^{\circ}$

(2) $15^{\circ}$

(3) $60^{\circ}$

(4) $45^{\circ}$

Show Answer

Answer: (3)

Solution:

For first minima a $\sin \theta=\lambda$

$\sin \theta=\frac{\lambda}{a}=\frac{1}{2}$

$\theta=30^{\circ}$

Angular spread $=60^{\circ}$