5 H.P., 50-Hz, 3-phase, 440 V, induction motors are available for the following r.p.m. Which motor will be the costliest ?
Correct answer: A. 730 r.p.m.
- A. 730 r.p.m.
- B. 960 r.p.m.
- C. 1440 r.p.m.
- D. 2880 r.p.m.
Explanation
For the same horsepower, the low-speed motor needs more poles and a larger active size to produce the required torque. Hence the 730-rpm motor is generally the costliest option.
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