Question

In Young's double slit experiment with monochromatic source of light of wavelength $6000A^{\circ }$, if the path difference is $1.5\times {10}^{-6}m$, the point becomes :

• A. bright band
• B. dark band
• C. sometimes bright and sometimes dark
• D. data insufficient

Answer 1

The correct option is B dark band

Here, $\frac{\Delta x}{\lambda }$
$=\frac{1.5\times {10}^{-6}}{6000\times {10}^{-10}}$
$=2.5$
So, here $\frac{\Delta x}{\lambda }$ is not integer
So, it is a dark bond because at dark
bond $\frac{\Delta x}{\lambda }$ is non integer.