What is the angular separation of two spectral lines of wavelengths 497 nm and 251 nm formed in the third order with a diffracting grating having 587 lines per millimeter?
A)34.8°
B)24.8°
C)41.3°
D)29.4°
E)4.21°

Question

Quizplus · Accepted Answer

Explanation:The angular separation between two spectral lines of wavelengths λ1 and λ2 formed in the nth order with a diffracting grating having N lines per millimeter is given by:θ = sin^-1[(nλ2 - nλ1)/d]where d is the grating spacing (1/N).Substituting the given values, we get:θ = sin^-1[(3 x 251 nm - 3 x 497 nm)/(1/587 mm)]= sin^-1(-0.00069)= 34.8°Therefore, the correct choice is A.

What Is the Angular Separation of Two Spectral Lines of Wavelengths