Suppose a water wave is moving from left to right in a water tank. The water tank is divided to two region (left and right) by an one-slit plastic plate. Which of the following(s) adjustment can increase the degree of diffraction of the wave ?
(1) Make the water of the whole tank deeper.
(2) Make the water in the right side deeper only.
(3) Make the water in the left side deeper only.
The Attempt at a Solution
I know (1) must be correct as it can increase wavelength. But I am not sure whether (2) and (3) is correct or not, please explain. Thanks