Answer:
The ruling separation must be between 2.2 × 10⁻⁶ m and 3.3 × 10⁻⁶ m
Explanation:
Fringe spacing w = λ·D/s
Diffraction grating, d·sin(θ) = n·λ
n = Number of lines
When θ = 90°, we have, sin(θ) = sin(90°) = 1
Therefore;
d·sin(θ) = d × 1 = d = n·λ
When n = 6 lines and d = 550-nm, we have;
d = 6 × 550-nm = 3,300 nm = 3.3 microns = 3.3 × 10⁻⁶ m
Therefore, the ruling separation must be between 2.2 × 10⁻⁶ m and 3.3 × 10⁻⁶ m.
