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This section includes 9 Mcqs, each offering curated multiple-choice questions to sharpen your Electric Drives knowledge and support exam preparation. Choose a topic below to get started.
1. |
Calculate the active power in a 788 resistor with 178 A current flowing through it. |
A. | 24.96 MW |
B. | 24.44 MW |
C. | 24.12 MW |
D. | 26.18 MW |
Answer» B. 24.44 MW | |
2. |
A 3-phase induction motor runs at almost 1000 rpm at no load and 950 rpm at full load when supplied with power from a 50 Hz, 3-phase supply. What is the corresponding speed of the rotor field with respect to the rotor? |
A. | 30 revolution per minute |
B. | 40 revolution per minute |
C. | 60 revolution per minute |
D. | 50 revolution per minute |
Answer» E. | |
3. |
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 |
Answer» E. | |
4. |
The slope of the V-I curve is 5 . Calculate the value of resistance. Assume the relationship between voltage and current is a straight line. |
A. | .3254 |
B. | .3608 |
C. | .3543 |
D. | .3443 |
Answer» E. | |
5. |
The frame of an induction motor is made of _________ |
A. | Aluminum |
B. | Silicon steel |
C. | Cast iron |
D. | Stainless steel |
Answer» D. Stainless steel | |
6. |
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 |
Answer» D. 0.05, 0.02 | |
7. |
Calculate the phase angle of the sinusoidal waveform z(t)=78sin(456 t+2 78). |
A. | 39 |
B. | 2 5 |
C. | 74 |
D. | 2 4 |
Answer» B. 2 5 | |
8. |
An 8-pole, 3-phase, 50 Hz induction motor is operating at a speed of 720 rpm. The frequency of the rotor current of the motor in Hz is __________ |
A. | 2 |
B. | 4 |
C. | 3 |
D. | 1 |
Answer» B. 4 | |
9. |
A three-phase slip ring induction motor is fed from the rotor side with the stator winding short-circuited. The frequency of the current flowing in the short-circuited stator is ____________ |
A. | Slip frequency |
B. | Supply frequency |
C. | The frequency corresponding to rotor speed |
D. | Zero |
Answer» B. Supply frequency | |