Question 533Electricity/Electronics - Assistant Engineer70% to pass
What would be the actual rotor speed for a 4-pole three-phase squirrel-cage induction motor operating at 60 Hz if the rotor slip is 3%?
AI Explanation
The correct answer is A) 1746 rpm.
To calculate the actual rotor speed, we need to use the formula:
Actual Rotor Speed = Synchronous Speed x (1 - Slip)
Where:
- Synchronous Speed = (120 x Frequency) / Number of Poles
- Slip = 3% or 0.03
Plugging in the values:
- Synchronous Speed = (120 x 60) / 4 = 1800 rpm
- Actual Rotor Speed = 1800 x (1 - 0.03) = 1746 rpm
The other options are incorrect because:
B) 1793 rpm is too high
C) 1800 rpm is the synchronous speed, not the actual rotor speed
D) 1854 rpm is too high
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