1. The problem statement, all variables and given/known data How is the amplitude of a wave affected if the slit separation remains same but slit width is 1.)Increased? 2.)Decreased? and why? 2. Relevant equations Intensity is proportional to the square of amplitude 3. The attempt at a solution I consider the amplitude as allowed "fatness" of a wave. The more slit width there is, the more wave can be "fat" and so it will have a greater amplitude.