253. If a single-phase motor runs hot the probable cause cannot be
A. blown fuses
B. low voltage
C. high voltage
D. shorted stator coils
254. For ceiling fans generally the single phase motor used is
A. capacitor-start type
B. split-phase type
C. permanent capacitor type
D. capacitor start and run type
255. The direction of rotation of universal motor can be reversed by
A. interchanging the brush leads
B. switching over from A.C. to D.C.
C. reversing the supply terminals
D. any of the above
256. Which of the following is most economical method of starting a single-phase induction motor?
A. Inductance-start method
B. Split-phase method
C. Resistance-start method
D. Capacitance-start method
257. When a universal motor is operated on no-load, its speed is limited by
A. supply voltage frequency
B. armature reaction
C. winding and friction
D. weight of the armature
258. What could be the size of a universal motor for use in vacuum cleaners?
A. 2 H.P.
B. 1 H.P.
C. 3/4 H.P.
D. 1/4 H.P.
259. Which of the following applications make use of a universal motor?
A. Portable tools
B. Lathe machines
C. Oil expeller
D. Floor polishing machine
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