A beam of light of $\lambda=600 \mathrm{~nm}$ from a distance source falls on a single alit $1 \mathrm{~mm}$ wide and the resulting diffraction pattern is observed on a screen $2 \mathbf{m}$ away. The distance between first dark fringes on either side of the central bright fringe is-
Option A $\quad 1.2 \mathrm{~cm}$
Option B $\quad 1.2 \mathrm{~mm}$
Option C $\quad 2.4 \mathrm{~cm}$
Option D $\quad 2.4 \mathrm{~mm}$

contexto.120

3 years ago

The correct option is D

Central maxima: Distance between the first dark fringes on either.

$=\frac{2 \lambda \mathrm{D}}{\mathrm{b}}=\frac{2 \times 600 \times 10^{-6} \times 2}{3 \times 10^{-3}} \mathrm{~m}$

$=2.4 \times 10^{-3} \mathrm{~m}$

$=2.4 \mathrm{~mm}$