In a series resonant circuit, the impedance of the circuit is ____ ?
A. Maximum
B. Minimum
C. Maximum
D. None of them
A.C Fundamentals, Circuits and Circuits Theory
Here are some Multiple Choice Questions (MCQs) on A.C Fundamentals, Circuits and Circuits Theory in Electrical Engineering.
The product of apparent power and cosine of the phase angle between circuit voltage and current is:
A. Volt-amperes
B. Instantaneous power
C. True power
D. Reactive power
In a pure inductive circuit:
A. The current leads the voltage by 90°
B. The current can lead or lag by 90°
C. The current is in phase with the voltage
D. The current lags behind the voltage by 90°
The frequency of an alternating current is ___ ?
A. The number of cycles generated in one minute
B. The number of electrons passing through a point in one second
C. The speed with which the alternator runs
D. The number of waves passing through a point in one second
Which of the following refers to a parallel circuit ?
A. The current through any one element is less than the source current
B. The equivalent resistance is greater than any one of the resistors
C. The current through each element is same
D. The voltage across element is in proportion to it’s resistance value
Skin effect occurs when a conductor carries current at ____ frequencies.
A. High
B. Medium
C. Very low
D. Low
Time constant of a capacitive circuit:
A. Increases with the increase of capacitance and decrease of resistance
B. Increase with increase of capacitance and increase of resistance
C. Increases with the decrease of capacitance and decrease of resistance
D. Increases with the decrease of capacitance and increase of resistance
Magnitude of current at resonance in R-L-C circuit ____ ?
A. Depends upon the magnitude of R, L and C
B. Depends upon the magnitude of R
C. Depends upon the magnitude of L
D. Depends upon the magnitude of C
Wire-wound resistors are unsuitable for use at high frequencies because they:
A. Are likely to melt under excessive eddy current heat
B. Consume more power
C. Exhibit unwanted inductive and capacitive effects
D. Create more electrical noise
The power is measured in terms of decibels in case of ____ ?
A. Current transformers
B. Auto transformers
C. Electronic equipment
D. Transformers