A six-pole three-phase squirrel-cage induction motor operating at 60 Hz is running at 1155 rpm. What is the percentage slip in this case?

Correct Answer: Option B — 3.75 %

Percentage slip is calculated as $\text{Slip} = [(N_s - N_r) / N_s] \times 100$. A 6-pole, 60 Hz motor has a synchronous speed of 1200 rpm. At 1155 rpm, slip is $[(1200 - 1155) / 1200] \times 100 = 3.75\text{%}$. IEEE 45 outlines standard motor operating parameters.