Photovoltaic cells are well known for their ability to convert solar energy (1) into electrical energy.
The frequency f is related to the wavelength

by the equation

where v is the speed of the wave in the rope.
We can see from the formula that, if v is kept constant, smaller frequency means larger wavelength. So, the rope with frequency 2 Hz will have the longest wavelength.
Those two words are antonyms ... two words with opposite meanings.
"Wax" means "grow".
"Wane" means "shrink".