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Which motor used most in industries?
DC motor
Induction motor
Stepper motor
All of above
Induction motor
The 3-phase Induction Motor, particularly the Squirrel Cage Induction Motor (SCIM), is the workhorse of industrial applications due to its rugged construction, low maintenance, and high reliability. It converts electrical energy into mechanical energy through electromagnetic induction without the need for brushes or complex excitation systems.
The 3-phase Induction Motor, particularly the Squirrel Cage Induction Motor (SCIM), is the workhorse of industrial applications due to its rugged construction, low maintenance, and high reliability. It converts electrical energy into mechanical energy through electromagnetic induction without the need for brushes or complex excitation systems.
NsтАЛ=P120fтАЛ тАФ Synchronous speed of the motor
s=NsтАЛNsтАЛтИТNrтАЛтАЛ тАФ Slip of the induction motor
When a 3-phase supply is fed to the stator windings, it produces a Rotating Magnetic Field (RMF). This RMF induces current in the rotor bars via Faraday's law of induction. The interaction between the RMF and the induced rotor current produces electromagnetic torque, causing the rotor to rotate at a speed slightly less than the synchronous speed (slip).
Most widely used AC motor in the world (approx 70-80% of industrial load).
Self-starting capability (in 3-phase versions).
Extremely robust and requires minimal maintenance as there are no sliding contacts/brushes.
Operates at a lagging power factor.
High efficiency and reliability
Low cost and simple design
Maintenance-free due to absence of brushes
Capable of operating in harsh environments
High starting current (inrush current)
Difficult to control speed compared to DC motors
Poor power factor at light loads
Pumps, fans, and compressors
Conveyor belts and industrial machinery
Machine tools and manufacturing plants
DC motors are used where precise speed control is required (e.g., rolling mills, electric traction).
Stepper motors are used for precise positioning in robotics and CNC machines, not for continuous industrial power loads.
B is correct тАФ The 3-phase Induction Motor is the most widely used motor in industries due to its simplicity, durability, and cost-effectiveness.
In exams, remember that Induction Motors are preferred for constant speed applications, whereas DC Motors or VFD-driven AC motors are chosen for variable speed requirements.