Eg2098 Industrial Electronics & Control

9 Questions

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Industrial Revolution Quizzes & Trivia


Questions and Answers
  • 1. 
    A shunt DC motor operates at 700 rpm when an armature of 18 A from a 230-V supply. If the armature resistance is 0.25W, calculate the no-load speed, assuming that all output losses are negligible.
    • A. 

      700.0 rpm

    • B. 

      778.5 rpm

    • C. 

      714.0 rpm

    • D. 

      687.2 rpm

  • 2. 
    Find the output torque of a DC motor whose output power is 1200 W and whose shaft speed is 1200 rpm.
    • A. 

      1.00 Nm

    • B. 

      60.0 Nm

    • C. 

      0.105 Nm

    • D. 

      9.55 Nm

  • 3. 
    A 110V series DC motor has an armature resistance of 0.3W and a field resistance of 0.2W. The motor is running off a 110V DC power supply and draws a line current of 20A and rotates at 1500 rpm while driving a mechanical load. The rotational loss of the motor is 250W. Calculate the efficiency of the motor.
    • A. 

      79.55%

    • B. 

      70.45%

    • C. 

      87.5%

    • D. 

      61.36%

  • 4. 
    A 3-phase, 6-pole, induction motor is supplied with a 240V, 50 Hz supply and draws a current of 35A at a power factor of 0.75 and has a full-load slip of 2.0%. The total copper loss and iron loss in the stator is 350W. Calculate the input power, Pin,  of the induction motor.
    • A. 

      14198 W

    • B. 

      10562 W

    • C. 

      10912 W

    • D. 

      14548 W

  • 5. 
    A 4-pole induction motor is energised by 3-phase, 50 Hz supply. The motor (rotor) runs on full-load at 5 percent slip. Determine:-                                        (i)  The speed of the rotating magnetic field (ns)                                        (ii) The frequency of the stator currents (fs)
    • A. 

      1,500 rpm, 50 Hz

    • B. 

      1,500 rpm, 2.5 Hz

    • C. 

      1,425 rpm, 50 Hz

    • D. 

      1,425 rpm, 2.5 Hz

  • 6. 
    A DC shunt motor is connected to 230 V DC power supply. The motor has an armature resistance of 0.8 ohm and a field resistance of 100 ohms. The motor draws a current of 12A and rotates at 300 rpm at full load. Find the input power.
    • A. 

      2760 W

    • B. 

      3000 W

    • C. 

      2880 W

    • D. 

      529 W

  • 7. 
    In the 3-phase induction motor, if the rotor moves at the same speed as the magnetic field
    • A. 

      The slip will be 1

    • B. 

      The torque will be maximum

    • C. 

      The slip will be zero

    • D. 

      The torque will remain unchanged

  • 8. 
    A 100V DC series motor runs at 1500 rpm with a line current of 20A. The armature resistance is 0.3W and the field resistance is 0.2W. Find the power developed.
    • A. 

      1800 W

    • B. 

      1880 W

    • C. 

      1920 W

    • D. 

      2000 W

  • 9. 
    An induction motor is running at a slip of 0.1. The input power is 2000W. The stator copper loss and core loss is 200W. The rotational loss is 50W. What is the rotor copper loss?
    • A. 

      1750W

    • B. 

      180W

    • C. 

      175W

    • D. 

      200W