Chapter 19, Problem 8STP

To determine

To Choose: The correct option.

Answer to Problem 8STP

Option A

Explanation of Solution

Given:

Wavelength of reflected red light, $\lambda =6.5\times {10}^{-7}\text{m}$

Refractive index of soap bubble, $\mu =1.41$

Formula used:

The minimum thickness of the soap bubble can be obtained using:

  $t=\frac{\left(2n+1\right)}{2\mu }\frac{\lambda }{2}$

Calculations:

For minimum thickness, n =0.

Substitute the values:

  $\begin{array}{c}t=\frac{\left(2n+1\right)\lambda }{4\mu }\\ =\frac{6.5\times {10}^{-7}}{4\times 1.41}\\ =1.2\times {10}^{-7}\text{m}\end{array}$

Conclusion:

Thus, option A is correct.