Question

Besides having an emf, what is necessary for an electric current to perform useful work?

Answer 1

In addition to having an electromotive force (emf), an electric current must also have a complete circuit through which it can flow in order to perform useful work. This means that there must be a continuous path for the electric charges to flow from the source of the emf, such as a battery or generator, through the load or device that is performing the work, and then back to the source.

The circuit must also have a load or device that can convert the electrical energy carried by the current into some other form of energy, such as light, heat, or mechanical work. For example, a light bulb converts electrical energy into light energy, and an electric motor converts electrical energy into mechanical energy to drive a machine.

Answer 2

To produce an electric current, three things are needed: a supply of electric charges (electrons) which are free to flow, some form of push to move the charges through the circuit and a pathway to carry the charges.

Step-by-step explanation: