• # question_answer What will be the angular width of central maxima in fraunhofcr diffraction, when tight of wavelength $(6000\overset{o}{\mathop{A}}\,)$ is used and slit width is $12\times {{10}^{-5}}cm$: A)  2rad               B)  3 radC)  1 rad             D)  2 rad

As, angular width $\theta =\frac{2\lambda }{d}=\frac{2\times 6000\times {{10}^{-1}}}{12\times {{10}^{-5}}\times {{10}^{-2}}}=1\,\,rad$ Note that the diffracted light is distributed in between, $-\frac{\lambda }{d}$to $+\frac{\lambda }{d}$