Question

If a soap bubble is 115 nm thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by white light? Assume that n = 1.33. Express your answer to three significant figures and include the appropriate units.

Answer 1

`611.8` nm

Step-by-step explanation:

`n_(oil)` = Index of refraction of soap bubble = 1.33

`t` = thickness of the soap bubble = 115 nm = 115 x 10⁻⁹ m

`\lambda` = wavelength of light = ?

`m` = order = 0

For reflection , the necessary condition is

`2 n_(oil) t = (m + 0.5) \lambda`

`2 (1.33)(115* 10^(-9))= (0 + 0.5) \lambda`

`\lambda = 6.118* 10^(-7)`

`\lambda = 611.8` nm