Final answer:
The air compressor governor typically cuts in at pressures between 100 psi and 125 psi for air brake systems, which is higher than the options provided in the question (10, 20, 30, 40 psi).
Step-by-step explanation:
In the context of air brake systems, specifically for heavy-duty vehicles, the air compressor governor controls the air pressure within the system's air tanks by dictating when the compressor will start (cut-in) and stop (cut-out) pumping air. Typically, the governor will cut in at a pressure that ensures the system has adequate air for braking and other functions. Without specific information regarding the vehicle or compressor model in question, it is generally accepted that cut-in pressures for air brake systems range between 100 psi and 125 psi, which does not include the options provided in the question (10, 20, 30, 40 psi). These figures are higher than the options given as they are meant to maintain safe operating pressures for effective braking. It is essential always to refer to the manufacturer's specifications for the precise cut-in and cut-out pressures for any given air compressor governor.