William asks…What is the definition and formula for Efficiency?What is the definition and formula for Efficiency? its for science homework.Nancy answers:The relationship between the Input & Output power gives the 'Efficiency' ( η ) of the machine, generally expressed as a 'Percentage' (%).
Efficiency (η) = Power out / Power in
% η = (P out / P in) x 100.
Example: A 3 kW motor is used to lift a load of
