Electrical Engineering ⇒ Topic : Generation of Alternating Voltages and Currents

Generation of Alternating Voltages and Currents

An alternating voltage may be generated

(1) by rotating a coil at constant angular velocity in a uniform magnetic field as shown in Fig. (a).

                                                        or

(2) by rotating a magnetic field at a constant angular velocity within a stationary coil as shown in Fig. (a).

In either case, the generated voltage will be of sinusoidal waveform. The magnitude of generated voltage will depend upon the number of turns of coil, the strength of magnetic field and the speed of rotation. The first method is used for small a.c. generators while the second method is employed for large a.c. generators                     

                                                                (a)                                                                                                                 (b)

                                                                                                            FIGURE