The practical illustration of the phenomenon of mutual induction is____________?

Related Mcqs:

1. 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...

2. The self inductances of two coils are 8 mH and 18 mH. If the co-efficients of coupling is 0.5, the mutual inductance of the coils is______________?

   A. 4 mH B. 5 mH C. 6 mH D. 12 mH...

3. Two coils have self-inductances of 10 H and 2 H, the mutual inductance being zero. If the two coils are connected in series, the total inductance will be_____________?

   A. 6 H B. 8 H C. 12 H D. 24 H...

4. Two 300 uH coils in series without mutual coupling have a total inductance of___________?

   A. 300 uH B. 600 uH C. 150 uH D. 75 uH...

5. As per Faraday’s laws of electromagnetic induction, an e.m.f. is induced in a conductor whenever it_______________?

   A. lies perpendicular to the magnetic flux B. lies in a magnetic field C. cuts magnetic flux D. moves parallel to the direction of the magnetic field...

6. 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...

7. _________________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...

8. 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...

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

   A. auto-transformer B. star-delta C. slip ring D. any of the above...

10. The cost of an induction motor will increase as________________?

    A. horsepower rating increases but r.p.m. decreases B. horsepower rating decreases but r.p.m. increases C. horsepower rating and operating speed increases D. horsepower rating and operating speed decreases...