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| Basis for Comparison | Stator | Rotor |
|---|---|---|
| Definition | It is a stationary part of the machine | It is the rotating part of the motor. |
| Parts | The outer frame, stator core, and stator winding. | Rotor winding and Rotor core |
| Supply | Three-phase Supply | DC supply |
| Winding Arrangement | Complex | Easy |
| Insulation | Heavy | Less |
| Friction Loss | High | Low |
| Cooling | Easy | Difficult |
| BASIS | MOTOR | GENERATOR |
|---|---|---|
| Function | The Motor converts Electrical energy into Mechanical Energy | The generator converts Mechanical energy to Electrical energy. |
| Electricity | It uses electricity. | It generates electricity |
| Driven element | The Shaft of the motor is driven by the magnetic force developed between armature and field. | The Shaft is attached to the rotor and is driven by mechanical force. |
| Current | In a motor, the current is to be supplied to the armature windings. | In the generator, the current is produced in the armature windings. |
| Rule Followed | Motor follows Fleming’s Left-hand rule. | The generator follows Fleming’s Right-hand rule. |
| Example | An electric car or bike is an example of an electric motor. | The energy in the form of electricity is generated at the power stations. |
An electrical insulator is a material in which the electron does not flow freely or the atom of the insulator has tightly bound electrons whose internal electric charges do not flow freely; very little electric current will flow through it under the influence of an electric field. This contrasts with other materials, semiconductors, and conductors, which conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals.
A perfect insulator does not exist because even insulators contain small numbers of mobile charges (charge carriers) that can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as the breakdown voltage of an insulator. Some materials such as glass, paper, and Teflon, which have high resistivity, are very good electrical insulators. A much larger class of materials, even though they may have lower bulk resistivity, are still good enough to prevent significant current from flowing at normally used voltages, and thus are employed as insulation for electrical wiring and cables. Examples include rubber-like polymers and most plastics which can be thermoset or thermoplastic in nature.
Insulators are used in electrical equipment to support and separate electrical conductors without allowing current through themselves. An insulating material used in bulk to wrap electrical cables or other equipment is called insulation. The term insulator is also used more specifically to refer to insulating supports used to attach electric power distribution or transmission lines to utility poles and transmission towers. They support the weight of the suspended wires without allowing the current to flow through the tower to the ground.
