What is the minimum thickness of a soap bubble for which the first order of cons
Practice Questions
Q1
What is the minimum thickness of a soap bubble for which the first order of constructive interference occurs for light of wavelength 600 nm?
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Questions & Step-by-Step Solutions
What is the minimum thickness of a soap bubble for which the first order of constructive interference occurs for light of wavelength 600 nm?
Step 1: Understand that a soap bubble has two surfaces: the outer surface and the inner surface.
Step 2: Know that when light hits the soap bubble, some light reflects off the outer surface and some reflects off the inner surface.
Step 3: Realize that for constructive interference to occur, the light waves reflecting from both surfaces must be in phase (they must align).
Step 4: Remember that when light reflects off a medium with a higher refractive index (like air to soap), it undergoes a phase change of 180 degrees (or half a wavelength).
Step 5: For the first order of constructive interference, the path difference between the two reflected light waves must equal one wavelength (λ).
Step 6: Since there is a phase change of 180 degrees for the light reflecting off the outer surface, the effective path difference becomes λ/2 for the first order of constructive interference.
Step 7: Therefore, the minimum thickness (t) of the soap bubble for the first order of constructive interference is t = λ/2.
Step 8: Substitute the given wavelength (λ = 600 nm) into the equation: t = 600 nm / 2.
