Which of the following machines has heavy fluctuation of load ?
Which of the following machines has heavy fluctuation of load ? A. Printing machine B. Punching machine C. Planer D. Lathe
Which of the following machines has heavy fluctuation of load ? A. Printing machine B. Punching machine C. Planer D. Lathe
In which of the following applications the load on motor changes in cyclic order ? A. Electric shovels B. Cranes C. Rolling millsD. All of the above
For derries and winches which of the following drives can be used ? A. Pole changing squirrel cage motors B. D.C. motors with Ward-leonard con-trol C. A.C. slip ring motors with variable resistanceD. Any of the above
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 motorD. slip ring induction motor
___________________has least range of speed control? A. Slip ring induction motorB. Synchronous motor C. D.C. shunt motor D. Schrage motor
Flame proof motors are used in_________________? A. paper mills B. steel mills C. moist atmospheresD. explosive atmospheres
In squirrel cage induction motors which of the following methods of starting cannot be used ? A. Resistance in rotor circuit B. Resistance in stator circuit C. Auto-transformer starting D. Star-delta starting
Heat control switches are used in__________________? A. transformersB. cooling ranges C. three phase induction motors D. single phase
In jaw crushers a motor has to often start against ____________________ load? A. heavy B. medium C. normal D. low
Which of the following motors is usually preferred for kiln drives ? A. Cascade controlled A.C. motor B. Slip ring induction motor C. Three phase shunt wound com-mutator motorD. Any of the above