Efficiency

How it is used

Efficiency = useful output ÷ total input, using either energy or power. The rest is 'wasted', usually as heat. Common phrases: energy efficiency, highly efficient, improve the efficiency. LED lamps are far more efficient than filament lamps.

Example sentences

1. The motor takes in 500 J and gives 300 J to the load, so its efficiency is 60%.

2. Lubricating the gears improves the efficiency of the machine.

Common collocations

• energy efficiency
• improve the efficiency
• percentage efficiency
• highly efficient
• efficiency of a machine

Related terms

• powerThe rate at which energy is transferred or work is done, in other words energy per second. It is measured in watts (W), where one watt is one joule per second.
• energyThe ability of a system to do work or cause change. It comes in many forms, such as kinetic, potential, thermal and chemical, and it is measured in joules (J).
• workThe energy transferred when a force moves an object through a distance in the direction of the force. It equals force times displacement and is measured in joules (J).
• frictionA force that acts between two surfaces in contact and opposes their sliding past each other. It usually turns kinetic energy into heat.
• first law of thermodynamicsThe principle that the change in a system's internal energy equals the heat supplied to it minus the work it does. It is the conservation of energy applied to heat and work.

This word in other fields

The same English word can have a different meaning in another field:

• efficiency · Mechanical Engineering

More terms: Energy, Work and Momentum

• kinetic energy
• potential energy
• conservation of energy
• momentum
• impulse
• elastic collision
• conservation of momentum