Question

The path difference between two wave fronts emitted by coherent sources of wavelength $5640\mathring{A}$ is $2.1$ microns. The phase difference between the wave fronts at that point is :

• A. $7.692$
• B. $7.692\pi$
• C. $\frac{7.692}{\pi }$
• D. $\frac{7.692}{3\pi }$

Answer 1

The correct option is B $7.692\pi$

phase difference is $\frac{d}{\lambda }\times 2\pi =\frac{2\pi \ast 2.1}{0.564}=7.692\pi$
option $B$ is correct