O. there are two gratings havingspcecaion b00 lines/mm and width 50 mm, and 1800 lines/mm and width 15 mm. ney are uscd to resolve whiic light. what will be the

o. There are two gratings havingspcecaiOn b00 lines/mm and width 50 mm, and 1800 lines/mm and width 15 mm. ney are uscd to resolve whiic light. What will be the maximum resolving Pow St order of the combination of two gratings ? (1) 3x10 (3) 81x10 (2) 57x10 4) 108x 10 (7)