Diffraction Practice Test

A student compares two ripple-tank setups with identical barriers and slit widths. Setup 1 uses waves with longer wavelength than setup 2. Both have the same amplitude. Which setup shows greater diffraction after the slit?

Ocean waves pass through a narrow gap between two piers. The gap width is about equal to the wavelength $\lambda$, and the waves spread into the region beyond. Compared to a much wider gap, the spreading is greater mainly because the gap is