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SoundsofPhysics
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Thread moved from the technical forums to the schoolwork forums
A Homework Question about double-slit interference reads as such:
"Finding a Wavelength from an Interference Pattern
Suppose you pass light from a He-Ne laser through two slits separated by 0.0100 mm and find that the third bright line on a screen is formed at an angle of 10.95° relative to the incident beam. What is the wavelength of the light?"
I used the equation:
d* sin *(theta) = m * lambda
0.01 * sin(10.95) = 2 * lambda
lambda = 949nm
The difference they did is using m = 3. But shouldn't the third line on the screen have m = 2 because the first line has m = 0 (It is the center, so theta = 0 and m must equal zero). Am thinking about it wrong? If so, how?
"Finding a Wavelength from an Interference Pattern
Suppose you pass light from a He-Ne laser through two slits separated by 0.0100 mm and find that the third bright line on a screen is formed at an angle of 10.95° relative to the incident beam. What is the wavelength of the light?"
I used the equation:
d* sin *(theta) = m * lambda
0.01 * sin(10.95) = 2 * lambda
lambda = 949nm
The difference they did is using m = 3. But shouldn't the third line on the screen have m = 2 because the first line has m = 0 (It is the center, so theta = 0 and m must equal zero). Am thinking about it wrong? If so, how?