Which of the following statements about efficiency is true?

Efficiency is a measure of how effectively a system converts input energy or work into useful output energy or work. It is quantified as the ratio of useful output to input, often expressed as a percentage. This calculation inherently limits efficiency to a maximum of 100%. If a machine or system were to exceed 100% efficiency, it would imply that it is producing more energy than is put into it, which violates the principle of energy conservation.

Therefore, the statement that efficiency is always less than or equal to 100% accurately reflects the physics governing work and energy in systems. This principle applies universally across mechanical systems, electrical devices, and any other energy-conversion processes. Hence, any situation claiming efficiencies above 100% would be fundamentally flawed from a scientific standpoint.