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 difference between synchronous speed and actual speed in induction motor is known as
Slip
Regulation
Backlash
Lag
Slip
Slip is defined as the relative speed difference between the synchronous speed (NsтАЛ) of the stator magnetic field and the actual rotor speed (NrтАЛ) of an induction motor. It is expressed either as a fraction of synchronous speed or as a percentage.
Slip is defined as the relative speed difference between the synchronous speed (NsтАЛ) of the stator magnetic field and the actual rotor speed (NrтАЛ) of an induction motor. It is expressed either as a fraction of synchronous speed or as a percentage.
s=NsтАЛNsтАЛтИТNrтАЛтАЛ тАФ slip expressed as a fraction
NsтАЛ=P120fтАЛ тАФ synchronous speed calculation where f is frequency and P is poles
In an induction motor, the stator winding produces a rotating magnetic field that travels at synchronous speed (NsтАЛ). The rotor rotates at speed (NrтАЛ) in the same direction, but must always be slower than NsтАЛ to maintain relative motion, which allows the stator field to cut the rotor conductors and induce a current via Faraday's Law of Electromagnetic Induction.
At standstill (rotor stationary), NrтАЛ=0, thus slip s=1 (or 100%).
If the rotor were to run at synchronous speed (NrтАЛ=NsтАЛ), slip would be zero, no torque would be developed, and the motor would stop.
Typical slip for an induction motor at full load ranges between 2% to 5%.
Provides a measure of the motor's loading condition
Critical parameter for calculating torque and efficiency
Increased slip results in higher rotor copper losses
Higher slip generally leads to lower operating efficiency
Industrial drive systems
Speed control in variable frequency drives (VFD)
Regulation refers to the voltage variation in transformers or machines from no-load to full-load.
Backlash is a mechanical play in gear systems.
Lag is a general term often related to phase difference in AC circuits, not specifically the speed difference in machines.
A is correct тАФ The difference between synchronous speed and rotor speed, expressed as a fraction of synchronous speed, is called Slip.
Remember that NsтАЛ depends only on stator frequency and number of poles; it is independent of the rotor speed. When solving problems, always check if slip is given as a fraction or a percentage.