What is Electric Motor ?

hi

For other kinds of motors, see Motor (disambiguation). For a railroad engine, see Electric locomotive.

An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate

through the interaction between the motor's magnetic field and winding currents to generate force in the form of rotation.

Electric motors can be powered by direct current (DC) sources, such as from batteries, motor vehicles or rectifiers, or by

alternating current (AC) sources, such as a power grid, inverters or electrical generators. An electric generator is mechanically

identical to an electric motor, but operates in the reverse direction, accepting mechanical energy (such as from flowing water)

and converting this mechanical energy into electrical energy.

Electric motors may be classified by considerations such as power source type, internal construction, application and type of

motion output. In addition to AC versus DC types, motors may be brushed or brushless, may be of various phase (see single-

phase, two-phase, or three-phase), and may be either air-cooled or liquid-cooled. General-purpose motors with standard

dimensions and characteristics provide convenient mechanical power for industrial use. The largest electric motors are used for

ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. Electric motors

are found in industrial fans, blowers and pumps, machine tools, household appliances, power tools and disk drives. Small

motors may be found in electric watches.

In certain applications, such as in regenerative braking with traction motors, electric motors can be used in reverse as generators to recover energy that might

otherwise be lost as heat and friction.

Electric motors produce linear or rotary force (torque) and can be distinguished from devices such as magnetic solenoids and loudspeakers that convert electricity into

motion but do not generate usable mechanical force, which are respectively referred to as actuators and transducers.

The first electric motors were simple electrostatic devices described in experiments by Scottish monk Andrew

Gordon and American experimenter Benjamin Franklin in the 1740s.[2][3] The theoretical principle behind them

Coulomb's law, discovered, but not published, by Henry Cavendish in 1771. This law was later discovered

independently by Charles-Augustin de Coulomb in 1785, who published it so that it is now known with his name

The invention of the electrochemical battery by Alessandro Volta in 1799[5] made possible the production of

persistent electric currents. After the discovery of the interaction between such a current and a magnetic field,