In ________________ method of staging three phase induction motors the starting voltage is not reduced?

Related Mcqs:

1. For three-phase induction motors which of the following is the least efficient method of speed control ?

   A. Cascade control
   B. Pole changing
   C. Rheostat control
   D. Combination of cascade and pole changing

2. _________________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

3. 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

4. need frequent starting and stopping of electric motors ?

   A. Paper mills
   B. Grinding mills
   C. Air-conditioners
   D. Lifts and hoists

5. A pony motor is used for the starting which of the following motors ?

   A. Squirel cage induction motor
   B. Schrage motor
   C. Synchronous motor
   D. None of the above

6. A series resonant band-stop filter consists of a 68 Ω resistor, a 110 mH coil, and a 0.02 µF capacitor. The internal resistance, RW, of the coil is 4 Ω. Input voltage is 200 mV. Output voltage is taken across the coil and capacitor in series. What is the output voltage magnitude at f0?

   A. 1.1 mV
   B. 11.1 mV
   C. 111 mV
   D. 200 mV

7. A series resonant band-pass filter consists of a 2 mH coil, a 0.005 µF capacitor, and a 120 Ω resistor. The winding resistance of the coil is 12 Ω. The output voltage is taken off the resistor. Input voltage is 12 Vrms. What is the output voltage magnitude at the center frequency (f0)?

   A. 10.9 V
   B. 1.09 V
   C. 1.1 V
   D. 12 V

8. In a CE amplifier, the phase difference between voltage across collector load RC and signal voltage is _________________?

   A. 180o
   B. 270o
   C. 90o
   D. 0o

9. A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is____________________?

   A. slop speed operation
   B. high starting torque
   C. low windage losses
   D. all of the above

10. A certain voltage divider consists of three 1 kΩ resistors in series. Which of the following load resistors will have the least effect on the output voltage?

    A. 1 MΩ
    B. 100 kΩ
    C. 1 kΩ
    D. 330 Ω