Question: The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656 nm (red) and 486 nm (blue). Light from a hydrogen lamp illuminates a diffraction grating with 510lines/mm , and the light is observed on a screen 1.7m behind the grating.
Part A: What is the distance between the first-order red and blue fringes?
I need help to calculate the distance between the first-order red and blue fringes.