Exam 24: Alternating Current Circuits

Which of the following is not affected by changing frequencies?

In a circuit with resistance and reactance, real power can be calculated as

Since parallel circuits with I_L and I_C have opposite phase angles, their phasor currents oppose each other and result in a single net reactive line current.

In parallel circuits I_L and I_C have opposite phase angles, the result is

All ______________ ac meters have scales calibrated in rms values unless noted otherwise on the meter.

The impedance angle of the series circuit is the angle whose

A ______________ does not dissipate power but stores energy in an electric or magnetic field.

In a circuit with both X_L and X_C, the opposite phase angles enable one to offset the effect of the other.

In general, when the series resistance and reactance are equal, Z_{T is}

The voltage across any capacitive reactance always lags its capacitive charge and discharge current by

The power factor is a numerical ratio with a value between 0 and 1 equal to the ______________ of the phase angle.

In a resistor, V and I are always out of phase.

The ______________ uses fixed coils to measure current in a circuit, and the moving coil measures voltage.

With regard to the phase angle for the capacitive reactance, the voltage across any X_C always leads its capacitive charge and discharge current by 90°.

The impedance angle of a series circuit is the angle whose tangent equals X/R.

The _____________ resultant of branch currents is the total line current.

Which of the following does not always have the same phase angle?

In series circuits, X_L is at 90° and X_C is at -90° which are opposite phase angles.

The ______________ power in watts can be calculated as I²R.

In order to realize efficient distribution of electric power in commercial applications, the power factor should be close to