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Current also results when a complete circuit is connected to that voltage. Electrical power is produced when there is both electrical pressure E (EMF) and current (I). Power = Current ×  Voltage (P = I × E) 

It is the relative motion between a conductor and a magnetic field that causes current to flow in the conductor. Either the conductor or magnet can be moving or stationary. When a magnet and its field are moved through a coiled conductor, as shown in Figure 9-7 , a DC voltage with a specific polarity is produced. The polarity of this voltage depends on the direction in which the magnet is moved and the position of the north and south poles of the magnetic field. The generator left-hand rule can be used to determine the direction of 

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 current flow within the conductor. [Figure 9-8]  Of course, the direction of current flow is a function of the polarity of the voltage induced in to the conductor. 

In practice, producing voltage/current using the process of electromagnetic induction requires a rotating machine. Generally speaking, on all aircraft, a generator or alternator employs the principles of electromagnetic induction to create electrical power for the aircraft. Either the magnetic field can rotate or the conductor can rotate. [Figure 9-9]  The rotating component is driven by a mechanical device, such as an aircraft engine. 

During the process of electromagnetic induction, the value of the induced voltage/current depends on three basic factors: 

1. Number of turns in the conductor coil (more loops equals greater induced voltage) 

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