67. The period of the grating d = 0.01 mm. What is the least number of strokes should contain a lattice to the two components of the yellow line of sodium (λ1 = 589,0 nm, λ2 = 589,6 nm) can be seen separately in the spectrum of the first order? Determine the smallest length L of the lattice.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)