Which amplifier property refers to the ratio of output-signal power compared to the total input power?

The property that describes the ratio of output-signal power to total input power is efficiency. Efficiency in an amplifier is a crucial specification as it indicates how effectively the amplifier converts input power into useful output power. It is typically expressed as a percentage and is calculated using the formula:

Efficiency (%) = (Output Power / Input Power) x 100

A high efficiency means that more of the input power is being converted into output, while a lower efficiency indicates more power is wasted, often as heat. This is particularly important in applications where thermal management is critical or when operating with limited power supplies.

Other concepts like gain refer to the increase in signal strength without considering power losses, while power factor deals with the phase difference between voltage and current in AC circuits, and linearity pertains to how faithfully the output signal represents the input signal. These terms relate to performance characteristics of an amplifier, but none directly address the ratio of output-to-input power like efficiency does.