Exam 21: Inductive Reactance

______________ reactance is equal to two times pi times frequency times inductance.

Very often X_L can be determined from voltage and current measurements.

Which of the following is not an example of how X_L is generally used?

When alternating current flows in an inductance,

The amount of current in an ac circuit with only inductive reactance is equal to the applied voltage divided by the inductance.

X_L is measured in ohms.

Inductive reactance is measured in ______________.

Although L can be determined when X_L and f are known, its value is determined strictly by its physical construction.

When ______________ current flows in an inductance, the amount of current is much less than the dc resistance alone would allow.

The constant factor 2? indicates the circular motion from which a sine wave is derived.

The inductive reactance of a coil is a result of the inductor's counter emf with a varying current.

For the most part, inductor values below what value are not practical for use in electronic circuits?

The general use of ______________ is to provide minimum reactance for relatively low frequencies but more for higher frequencies.

The inductive reactance is the ohms of opposition that an inductance has for sine-wave current.

The combined parallel inductive reactance branch will be

The values of X_L in series or in parallel are combined

With iron-core coils, the hysteresis and eddy-current losses

What is the inductive reactance for steady direct current?

With iron-core coils, the hysteresis and eddy-current losses ______________ with frequency.

The polarity of a coil's counter emf is always such that