Contact protection methods are designed to mitigate the wear and degradation occurring during the normal use of contacts within an electromechanical switch, relay or contactor and thus avoid an excessive increase in contact resistance or switch failure.

Contact electrification was an erroneous scientific theory from the Enlightenment that attempted to account for all the sources of electric charge known at the time.

Contact cleaner, also known as switch cleaner, is a term for a chemical, or a mixture of chemicals, intended to remove or prevent the build-up of oxides or other unwanted substances on the conductive surfaces of connectors, switches and other electronic components with moving surface contacts, and thus reduce the contact resistance encountered.

Contact bounce (also called chatter) is a common problem with mechanical switches and relays, which arises as the result of electrical contact resistance phenomena at interfaces.

A fusebox that is used to control and give out electricity around the home.

Fuel temperature coefficient of reactivity is the change in reactivity of the nuclear fuel per degree change in the fuel temperature.

A fuel tank (also called a petrol tank or gas tank) is a safe container for flammable fluids.

A fuel pump is a component in motor vehicles that transfers liquid from the fuel tank to the carburetor of the internal combustion engine.

A household is said to be in fuel poverty when its members cannot afford to keep adequately warm at a reasonable cost, given their income.

Fuel derived from the distillation of crude oil. There are a number of variations such as Heavy, medium and light fuel oils which have differering specifications such as specific gravity and calorific value.

Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector.

Fuel gas is any one of a number of fuels that are gaseous under ordinary conditions.

A fuel element failure is a rupture in a nuclear reactor's fuel cladding that allows the nuclear fuel or fission products, either in the form of dissolved radioisotopes or hot particles, to enter the reactor coolant or storage water.

A measure of how well fuel can be converted into mechanical work or motion.

A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions.

The fuel cladding is the first layer of protection around the nuclear fuel and is designed to protect the fuel from corrosion that would spread fuel material throughout the reactor coolant circuit.

The fuel assembly of nuclear fuel usually consisting of uranium or uranium–plutonium mixes.

A fuel is any material that can be made to react with other substances so that it releases energy as heat energy or to be used for work.

Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.

Fresh water is any naturally occurring water except seawater and brackish water. Fresh water is generally characterized by having low concentrations of dissolved salts and other total dissolved solids.