Top 150+ Solved Electrical Drives and Controls (EDC) MCQ Questions Answer
Q. To get the speed of DC motor below the normal speed without wastage of electrical energy we use
a. ward leonard control
b. rheostatic control
c. any of the ward leonard or rheostatic method can be used
d. not possible
Q. can give uniform speed variation
a. in both directions
b. in one direction
c. below normal speed only
d. above normal speed only.
Q. control method is
a. high initial cost
b. high maintenance cost
c. low efficiency at high loads
d. high cost, high maintenance and low efficiency
Q. TOPIC 5.1 SPEED CONTROL OF THREE PHASE INDUCTION MOTOR
a. slip frequency
b. supply frequency
c. the frequency corresponding to rotor speed
d. zero
Q. Calculate the moment of inertia of the thin spherical shell having a mass of 73 kg and diameter of 36 cm.
a. 1.56 kgm2
b. 1.47 kgm2
c. 1.38 kgm2
d. 1.48 kgm2
Q. A 50 Hz, 4poles, a single phase induction motor is rotating in the clockwise direction at a speed of 1425 rpm. The slip of motor in the direction of rotation & opposite direction of the motor will be respectively.
a. 0.05, 0.95
b. 0.04, 1.96
c. 0.05, 1.95
d. 0.05, 0.02
Q. The frame of an induction motor is made of
a. aluminum
b. silicon steel
c. cast iron
d. stainless steel
Q. In an induction motor, when the number of stator slots is equal to an integral number of rotor slots
a. there may be a discontinuity in torque slip characteristics
b. a high starting torque will be available
c. the maximum torque will be high
d. the machine may fail to start
Q. rotor?
a. 30 revolution per minute
b. 40 revolution per minute
c. 60 revolution per minute
d. 50 revolution per minute
Q. an external voltage source is in phase with the main voltage then speed will
a. increase
b. decrease
c. remain unchanged
d. first increases then decrease
Q. phase with the main voltage then speed will
a. increase
b. decrease
c. remain unchanged
d. first increases then decrease