The size of an excavator is usually expressed in terms of_________________?
(A) ‘crowd’ motion
(B) angle of swing
(C) cubic metres
(D) travel in metres
_________________method of starting a three phase induction motor needs six terminals ?
(A) Star-delta
(B) Resistance starting
(C) Auto-transformer
(D) None of the above
Which of the following is essentially needed while selecting a motor ?
(A) Pulley
(B) Starter
(C) Foundation pedal
(D) Bearings
In which of the following applications variable speed operation is preferred ?
(A) Exhaust fan
(B) Ceiling fan
(C) Refrigerator
(D) Water pump
Battery operated scooter for braking uses__________________?
(A) plugging
(B) mechanical braking
(C) regenerative braking
(D) rheostatic braking
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 mills
(D) All 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 motor
(D) slip ring induction motor
Flame proof motors are used in_________________?
(A) paper mills
(B) steel mills
(C) moist atmospheres
(D) 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