Final answer:
Wing fuel probes provide voltage output that is proportional to the fuel level in the wing tank.
Step-by-step explanation:
The wing fuel probes are devices used to measure the fuel level in the wings of an aircraft. There are typically two probes per wing, one in the inner part and one in the outer part. Each probe provides a voltage output that is proportional to the fuel level in the wing it is located. By measuring the voltage output of these probes, the pilot or operator can determine the amount of fuel remaining in the aircraft's wing tanks.