Which term describes the total load seen by the CT secondary?

The term that describes the total load seen by the CT (current transformer) secondary is "Burden." In electrical terms, the burden refers to the total impedance connected to the secondary winding of the current transformer. This includes the combined effects of the measuring instruments, relays, and any other devices or loads connected to the secondary circuit.

Understanding this concept is crucial because the burden directly impacts the accurate operation of the current transformer. If the burden is too high, it can cause an increase in the error of the current measurement and potentially saturate the transformer, leading to distorted readings.

The other terms mentioned do not capture this specific relationship. Load Factor pertains to the ratio of the actual load over a period to the maximum load possible, which does not specifically define the impedance on the secondary side of a CT. Transformer Ratio describes the relationship between primary and secondary voltages or currents in transformers but does not address the total load on the secondary. Amplifier Output generally refers to the output signal level from an amplifier, which is unrelated to the burdens imposed on a CT. Therefore, the term "Burden" is the most appropriate choice to describe the total load seen by the CT secondary.