試題詳解

55. Two sources of light illuminate a double slit simultaneously. One has wavelength 570 nm and the second has an unknown wavelength. The fifth bright fringe (m=5) of the unknown wavelength overlaps the forth bright fringe (m=4) of the light of 570 nm wavelength. What is the unknown wavelength?
(A) 326 nm
(B) 380 nm
(C) 456 nm
(D) 512 nm
(E) 713 nm