The diameter of the rotor shaft for an electric motor depends on which of the following ?
Correct answer: C. Horse power and r.p.m.
- A. r.p.m. only
- B. Horse power only
- C. Horse power and r.p.m.
- D. Horse power, r.p.m. and power factor
Explanation
Shaft size is governed mainly by the torque that must be transmitted, and torque is proportional to horsepower divided by speed. Hence both horsepower and r.p.m. determine the required shaft diameter.
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