⚡Electrical Engineering MCQs
Electrical Engineering MCQs
499 MCQs71
Which of the following motors is used for elevators ?
AInduction motor
BSynchronous motor
CCapacitor start single phase motor
DAny of the above
72
When a bogie negotiates a curve, reduction in adhesion occurs resulting in sliding. Thus sliding is acute when_______________?
Aand
BD. none of the above
Cboth
73
When the load is above _______________ a synchronous motor is found to be more economical?
A2 kW
B20 kW
C50 kW
D100 kW
74
Light duty cranes are used in which of the following ?
APower houses
BPumping stations
CAutomobile workshops
DAll of the above
75
Which of the following motors are pre-ferred for overhead travelling cranes ?
ASlow speed motors
BContinuous duty motors
CShort time rated motors
DNone of the above
76
In which of the following applications the load on motor changes in cyclic order ?
AElectric shovels
BCranes
CRolling mills
DAll of the above
77
For derries and winches which of the following drives can be used ?
APole changing squirrel cage motors
BD.
Cslip ring motors with variable resistance
DAny of the above
78
In case of _______________ speed control by injecting e.m.f. in the rotor circuit is possible?
Ad.
Bschrage motor
Csynchronous motor
Dslip ring induction motor
79
___________________has least range of speed control?
ASlip ring induction motor
BSynchronous motor
Cshunt motor
DSchrage motor
80
Flame proof motors are used in_________________?
Apaper mills
Bsteel mills
Cmoist atmospheres
Dexplosive atmospheres