Chapter 19, Problem 6STP

To determine

To Choose: The correct option.

Answer to Problem 6STP

Option B

Explanation of Solution

Given:

Distance between center bright band to third order bright band, $y=7.5\text{cm = 0}\text{.075 m}$

Distance between screen and the slits, $D=2.475\text{m}$

Order, $n=3$

Wavelength of laser beam, $\lambda =638\text{nm}\text{=}\text{638}\times {\text{10}}^{-9}\text{m}$

Formula used:

The distance between the slits $\left(d\right)$ can be obtained by:

  $d=\frac{Dn\lambda }{y}$

Calculations:

Substitute the values:

  $\begin{array}{c}d=\frac{Dn\lambda }{y}\\ =\frac{2.475\times 3\times 638\times {10}^{-9}}{0.075}\\ =6.3\times {10}^{-5}\text{m}\end{array}$

Conclusion:

Thus, option B is correct.