If it is desired to determine the average temperature across a large duct, what thermocouple wiring technique can be used to generate an emf proportional to the average temperature?

Correct Answer: Option B — Multiple thermocouples can be used if they are wired in parallel, where the sum of the individual voltages is divided by the number of thermocouples.

Wiring thermocouples in parallel creates an averaging circuit where the output voltage represents the mean temperature of the junctions. This technique is effective for monitoring large ducts where temperature gradients exist, providing a single representative signal for control systems without requiring complex individual sensor processing.