White light is incident on a soap film of `mu = 4//3` at an angle of `45^@`. On examining the transmitted light with a spectrometer, a bright band of wavelength `5400 Å` is found. What will be the minimum thickness of the soap film?

Explanation

To find the minimum thickness of the soap film that produces a bright band of wavelength 5400 Å when white light is incident at an angle of 45°, we can follow these steps:

### Step 1: Understand the given data
- Refractive index of soap film, \( \mu = \frac{4}{3} \)
- Angle of incidence, \( I = 45^\circ \)
- Wavelength of light, \( \lambda = 5400 \, \text{Å} = 5400 \times 10^{-10} \, \text{m} = 5.4 \times 10^{-7} \, \text{m} \)

### Step 2: Apply Snell's Law
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