A physics laboratory uses two monochromatic light sources, one emitting deep–red light of wavelength 700 nm and the other emitting blue–violet light of wavelength 420 nm. Each beam, in turn, passes through the same narrow single rectangular slit of width 0.080 mm and then travels 1.5 m to a distant viewing screen.
Answer the following questions about the diffraction patterns that appear on the screen.
(a) Without performing any numerical calculation, state which color of light produces the wider central bright maximum on the screen.
(b) Provide a clear qualitative explanation for your choice in part (a), explicitly relating the relevant physical quantities and their roles in single–slit diffraction.