Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
The efficiency of a 60 Hz, 6-pole, 1000 rpm 3-phase induction motor is ________.
The efficiency of an induction motor depends on factors such as slip, copper losses, core losses, and mechanical losses. Given the constraints of the motor's operation, the standard efficiency rating for medium-sized industrial induction motors typically falls in the range of 80%тИТ90%.
IS 12615:2018 (Efficiency classes for three-phase AC induction motors)
The efficiency of an induction motor depends on factors such as slip, copper losses, core losses, and mechanical losses. Given the constraints of the motor's operation, the standard efficiency rating for medium-sized industrial induction motors typically falls in the range of 80%тИТ90%.
╬╖=PinтАЛPoutтАЛтАЛ├Ч100% тАФ Efficiency calculation formula
NsтАЛ=P120fтАЛ тАФ Synchronous speed formula
s=NsтАЛNsтАЛтИТNrтАЛтАЛ тАФ Slip calculation
An induction motor converts electrical energy into mechanical energy through electromagnetic induction. The efficiency is defined as the ratio of mechanical output power to the electrical input power, expressed as ╬╖=PinтАЛPoutтАЛтАЛ├Ч100%.
Efficiency varies based on load conditions and motor design (standard vs premium efficiency).
Operating at rated frequency and voltage is critical to maintaining peak efficiency.
Higher efficiency motors utilize better quality magnetic steel and increased copper volume to reduce losses.
High operating efficiency in steady-state conditions.
Robust construction requiring minimal maintenance.
Efficiency drops significantly at light loads.
Power factor is typically lagging and decreases further at low loads.
Industrial pumps and fans.
Conveyor systems and industrial compressors.
The synchronous speed of a 6-pole, 60 Hz motor is NsтАЛ=6120├Ч60тАЛ=1200┬аrpm.
With a rotor speed of 1000┬аrpm, the slip is s=12001200тИТ1000тАЛ=16.6%. This relatively high slip indicates that the motor is operating significantly below its synchronous speed, affecting its efficiency profile.
C is correct тАФ 83.4% represents the standard efficiency range for this specific configuration of a 3-phase induction motor.
Always verify the synchronous speed NsтАЛ using NsтАЛ=120f/P first; if the given speed NrтАЛ is far from NsтАЛ, expect lower efficiency due to higher rotor copper losses (I2RrтАЛ losses).
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants