Question

Find the angular fringe width in a Young's double slit experiment with green light of wavelength $6000\mathring{A}$. The separation between the slits is $3\times {10}^{-3}\text{m}$.

• A. $1\times {10}^{-4}\text{rad}$
• B. $1\times {10}^{-4}\text{degree}$
• C. $2\times {10}^{-4}\text{rad}$
• D. $2\times {10}^{-4}\text{degree}$

Answer 1

The correct option is C $2\times {10}^{-4}\text{rad}$

Given:
$\lambda =6000\mathring{A}=6\times {10}^{-7}\text{m}$
$d=3\times {10}^{-3}\text{m}$

The angular fringe width is given by,

$\theta =\frac{\lambda }{d}=\frac{6\times {10}^{-7}}{3\times {10}^{-3}}$

$\Rightarrow \theta =2\times {10}^{-4}\text{rad}$

Hence, $\left(C\right)$ is the correct answer.