Question

In Young's double slit experiment ,wavelength of light is $6000\mathring{A}$ The the phase difference between the light waves reaching the third bright fringe from the central fringe will be:

• A. $0$
• B. $2\pi$
• C. $4\pi$
• D. $6\pi$

Answer 1

The correct option is D $6\pi$

Given that,

Wave length $\lambda =6000\stackrel{\circ }{A}$

Phase difference =$\varphi$

Now, the phase difference is

$\varphi =\frac{2\pi }{\lambda }\times n\lambda$

$\varphi =2\pi \times 3$

$\varphi =6\pi$

Hence, the phase difference is $6\pi$