The fundamental basis of construction for both a generator and motor is Faraday’s law of Induction. (Faraday’s Law of Induction: The induced electromotive force in any closed circuit is equal to the negative of the time rate of change of the magnetic flux enclosed by the circuit. Source: Wikipedia).
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Generators and motor both have current carrying loops which are rotated in a magnetic field. The loops are wrapped around an armature. An Armature is made up of iron core hence here the magnetic field becomes pretty strong. The direction of the current in the loops is then reversed resulting in movement. This motion creates what is called EMF or electromotive force. Hence converting one form of energy into another. In this case mechanical energy to electrical and vice-versa.
Let us now study the differences between a generator and a motor
|Mechanical energy is utilized to cause motion in the loops.||Electrical energy is utilized to cause the motion in loops.|
|EMF generated is sine wave varying with time.||Induction is used in this case.|
|The direction of the current produced is governed by fleming’s right-hand rule*||The direction of the current produced is governed by Fleming’s left-hand rule|
|A shaft and rotor mechanism is used which is driven by mechanical power.||Here the mechanical force is generated by the movement of the shaft due to interactions between the field and the armature|
|Armature winding is the point from where the electric current is emitted||Here the electricity is supplied to the armature winding, which results in the operation of the motor|
|A generator owing to its operational design needs more maintenance.||A motor requires minimal maintenance.|
|Used for power generation applications||Used for pumping water or other things as the case may be.|
*Flemings Right Hand Rule: This rule governs the direction of current in case of a generator.
The right hand is held with the thumb, index finger and middle finger mutually perpendicular to each other.
- The thumb is pointed in the direction of the motion of the conductor relative to the magnetic field.
- The first finger is pointed in the direction of the magnetic field. (north to south)
- Then the second finger represents the direction of the induced or generated current within the conductor (from the terminal with the lower electric potential to the terminal with higher electric potential, as in a voltage source)
*Flemings Left Hand Rule:
The left-hand rule of Fleming is the governing principle for the direction of current in case of a motor.
- The Thumb represents the direction of the Thrust on the conductor / Motion of the Conductor
- The Forefinger represents the direction of the Magnetic Field
- The Centre finger represents the direction of the Current.