When a first-order spectrum is examined by means of a one-inch grating having 10,000 lines/inch,the resolving power is R.When a second-order spectrum is examined by means of a two-inch grating having 20,000 lines/inch,the resolving power is
A)R/4
B)R/2
C)2R
D)4R
E)8R

Question

Quizplus · Accepted Answer

The resolving power (R) of a grating is given by the formula R = nN, where n is the order of the spectrum and N is the total number of lines on the grating. For the first case, n = 1 and N = 10,000, so R = 1*10,000. For the second case, n = 2 and N = 2*20,000 = 40,000, so the resolving power is 2*40,000 = 80,000, which is 8 times the original R.

When a First-Order Spectrum Is Examined by Means of a One-Inch