To calculate the frequency of a wave, we need to use the formula:
Frequency = 1 / Time
In this case, you mentioned that a wave produced by a source in two seconds has a wavelength of 2. However, it's not clear what unit of measurement you are using for the wavelength. Please provide the unit of measurement for the wavelength (e.g., meters, centimeters, etc.), so I can assist you in calculating the frequency accurately.