Consider a parallel beam of monochromatic light incident normally on a thin soap film suspended in air. The colorful interference pattern observed on the film surface is primarily governed by which physical phenomenon?

💡 Solution & Explanation

The iridescent colors seen on thin soap films arise from the interference of light waves reflected from the outer and inner boundary surfaces of the transparent film. Path length differences and phase changes upon reflection determine whether specific wavelengths undergo constructive or destructive interference for a given film thickness. Polarization involves restricting transverse wave vibrations to a single plane, which does not produce multicolored spatial fringes. The wavelength of visible light ranges approximately from 400 to 700 nanometers.