1. The problem statement, all variables and given/known data The question is regarding Young's double slit experiment. "Describe the effect, if any, on the separation and on the maximum brightness of the fringes when the following changes are made. ... ... 2) The wavelength λ is increased to 1.5λ, keeping a and D constant. Separation: Maximum brightness: 2. Relevant equations λ=ax/D 3. The attempt at a solution My answer: Separation: Increases by 1.5 times Maximum brightness: Same (Wrong, answer: less bright) Why would the change in wavelength alter the brightness of the fringes?