Join 60,000+ competitive exam aspirants
or with email
Your Cart
Subtotal₹0
Total₹0
Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
Join 60,000+ competitive exam aspirants
4 pole 3 phase 50 Hz I.M. has slip of 4% then speed N is
1440
1460
1480
1500
1440
Given: Poles P = 4, Frequency f = 50 Hz, Slip s = 4% (0.04)
Poles P = 4, Frequency f = 50 Hz, Slip s = 4% (0.04)
Ns=P120×f,N=Ns(1−s)
Calculate Synchronous Speed
The synchronous speed Ns is determined by the frequency f and number of poles P.
Ns=4120×50=1500 rpm
Apply Slip formula
The actual rotor speed N is calculated using the synchronous speed Ns and the slip s.
N=Ns(1−s)=1500(1−0.04)
Final Calculation
Multiplying the values gives the actual speed of the induction motor.
N=1500×0.96=1440 rpm
A is correct because substituting the given values into the speed equation yields a rotor speed of 1440 rpm.
Understanding the relationship between synchronous speed and slip is essential for solving problems in AC machine performance and torque-slip characteristics.