Besides a constant speed a synchronous rotor possesses which of the following advantages ?

Related Mcqs:

1. In case of _______________ speed control by injecting e.m.f. in the rotor circuit is possible?

   A. d.c. shunt motor B. schrage motor C. synchronous motor D. slip ring induction motor...

2. The diameter of the rotor shaft for an electric motor depends on which of the following ?

   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...

3. ________________ motor is a constant speed motor?

   A. Synchronous motor B. Schrage motor C. Induction motor D. Universal motor...

4. In a paper mill where constant speed is required________________?

   A. synchronous motors are preferred B. A.C. motors are preferred C. individual drive is preferred D. group drive is preferred...

5. Rotor of a motor is usually supported on ___________________ bearings?

   A. ball or roller B. needle C. bush D. thrust...

6. A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is____________________?

   A. slop speed operation B. high starting torque C. low windage losses D. all of the above...

7. An aeroplane of wingspan 10m flies from the equator towards the North Pole. The wings are perpendicular to the vertical component of the earths magnetic field (B = 4×10-5T). At maximum speed an emf of 96mV is induced across the wing tips. The maximum speed of the aeroplane is____________?

   A. 150msec-1 B. 384msec-1 C. 38.4msec-1 D. 200msec-1...

8. When the load is above _______________ a synchronous motor is found to be more economical?

   A. 2 kW B. 20 kW C. 50 kW D. 100 kW...

9. Among the logic families, the family which can be used at very high frequency greater than 100 MHz in a 4 bit synchronous counter is__________________?

   A. TTLAS B. CMOS C. ECL D. TTLLS...

10. Which of the following motors is preferred when quick speed reversal is the main consideration ?

    A. Squirrel cage induction motor B. Wound rotor induction motor E. Synchronous motor D. D.C. motor...