What is the highest order (the m value)of the complete visible spectrum (390 nm to 710 nm)that can be obtained with a grating having 300 lines/mm?
A) 5
B) 9
C) 8
D) 4

Question

Quizplus · Accepted Answer

The grating equation is mλ = d sin θ, where m is the order, λ is the wavelength, d is the grating spacing, and θ is the angle. The maximum order m is determined by the shortest wavelength (390 nm) and the grating spacing (1/300 mm = 3333.33 nm). Solving for m gives m = d/λ = 3333.33/390 ≈ 8.54. Since m must be an integer, the highest possible order is 4.

What Is the Highest Order (The M Value)of the Complete