The first order maximum caused by a double slit illuminated with light of wavelength 625 nm is found at some spot on a screen. The light source is changed to a new wavelength which places its second order (m=2) maxima at the same spot where the 625 nm first order maxima used to lie.
(a) What is the wavelength of the new light source?
(b) Is this wavelength is the visible range?
