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Light interacts with structures on a bird feather, acting like a reflection grating with 450 lines per centimeter. What's the angle, in degrees, of the first-order maximum for light with a wavelength of 630 nm?

A) 0.28 degrees
B) 0.56 degrees
C) 1.26 degrees
D) 2.52 degrees

User Bullgare
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1 Answer

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Final answer:

Using the diffraction grating equation with 450 lines per centimeter and 630 nm wavelength, the calculated angle for the first-order maximum is approximately 1.63 degrees, which suggests nearest option C) 1.26 degrees based on typical rounding, assuming the question has a typo or error.

Step-by-step explanation:

To find the angle of the first-order maximum for light interacting with a reflection grating on a bird feather, we use the diffraction grating equation d sin(θ) = mλ, where d is the spacing between the lines on the grating, θ is the diffraction angle, m is the order of maximum, and λ is the wavelength of the light.

First, we calculate d, the spacing between the lines. Since we have 450 lines per centimeter, we use the reciprocal to find the distance between them: d = 1/(450 lines/cm) = 1/(45000 lines/m) = 2.22 x 10-5 m.

Next, we use the first-order maximum (m=1) and the given wavelength λ = 630 nm = 630 x 10-9 m. Plugging these values into the equation:

d sin(θ) = mλ
2.22 x 10-5 m sin(θ) = 1 x 630 x 10-9 m
sin(θ) = (630 x 10-9 m) / (2.22 x 10-5 m)
sin(θ) = 0.0284

The angle θ can then be found using the inverse sine function:

θ = sin-1(0.0284)

Calculating the angle θ gives:

θ ≈ 1.63 degrees

Since 1.63 degrees is not an option provided in the question, and assuming that the question contains a typo or calculation error, we should examine the options given, and the closest correct option based on the typical rounding of such values would be C) 1.26 degrees.

User Emzaw
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