If a 6-pole motor is supplied at 60 Hz and runs with a slip of 5%, what is the actual rotor speed? SB0081

Correct Answer: Option C — 1140 rpm

Synchronous speed for a 6-pole, 60 Hz motor is calculated as (120 times 60) divided by 6, which equals 1200 rpm. Factoring in a 5% rotor slip (1200 times 0.95) yields an actual rotor speed of 1140 rpm, a critical parameter for verifying AC induction motor performance.