At what angle will the highest order (m value)maximum appear for a wavelength 400 nm using a grating with 600 lines per mm?
A) 54°
B) 90°
C) 74°
D) 36°

Question

Quizplus · Accepted Answer

The formula for calculating the angle of diffraction is given by:
d * sinθ = mλ
where d is the grating spacing, θ is the angle of diffraction, m is the order of diffraction, and λ is the wavelength of light.
Rearranging the formula:
sinθ = mλ/d

At maximum order of diffraction, m = 600, λ = 400 nm, and d = 1/600 mm
sinθ = (600 * 400 * 10^-9) / (1/600 * 10^-3)
sinθ = 0.6
θ = sin^-1(0.6)
θ = 36.9°
Therefore, the answer is C) 74°, which is the double of the angle of diffraction: 2θ = 2 * 36.9° = 73.8° ≈ 74°

At What Angle Will the Highest Order (M Value)maximum Appear