AC Circuit objective questions (mcq) and answers

31.  Change in circuit voltage will affect

   A. Resonant frequency

   B. Q

   C. Current

   D. Bandwidth

32.  An alternator is delivering power to a balanced load at unity power factor. The phase angle between the line voltages and the line current is

   A. 80^o

   B. 60^o

   C. 30^o

   D. 0^o

33.  To improve the power factor in three phase circuits, the capacitor bank is connected in Delta to make

   A. Capacitance calculation easy

   B. Capacitance very small

   C. The connection elegant

   D. The power factor correction more effective

34.  In a three-phase supply, floating neutral is undesirable because it may result in........across the load.

   A. Unequal line voltages

   B. High voltage

   C. Low-voltage

   D. None of the above

35.  A current is said to be direct current when its

   A. Magnitude remains constant with time

   B. Magnitude changes with time

   C. Direction changes with time

   D. Magnitude and direction changes with time

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