Question

The widths of the lines produced by monochromatic light falling on a diffraction grating can be reduced by:?
The correct answer is:
increasing the number of rulings without changing their spacing

why? thanks!!

Answer 1

The resolving power of a grating is R = nm where n is the order number and m is the total number of lines on the grating. So the larger total number of lines will do it. Changing from order 1 to order 2 also will do it