Question 1

In an AC circuit that contains only inductance, the current is limited only by the value of ____.&#10;A) impedance&#10;B) pure inductance&#10;C) resistance&#10;D) inductive reactance

Accepted Answer

In an AC circuit that contains only inductance, the current is limited only by the value of inductive reactance (Xᴸ). This is because inductors have the property of opposing changes in the current passing through it, and this opposition is measured in ohms as inductive reactance. The higher the inductive reactance, the greater the opposition offered by the inductor to the current flow. Therefore, the current in an inductor-dominated AC circuit is limited by the value of inductive reactance, and not by resistance or impedance.

Question 2

The voltage and current in a pure-resistive circuit are out of phase with each other.

Accepted Answer

In a pure-resistive circuit, voltage and current are in phase with each other. This means that the voltage and current both reach their maximum and minimum values at the same time, and they also cross the zero line at the same time. There is no phase difference between them.

Question 3

In a pure-____ circuit, the voltage and current are in phase with each other.&#10;A) inductive&#10;B) reactive&#10;C) capacitive&#10;D) resistive

Accepted Answer

In a pure resistive circuit, the voltage and current are in phase with each other. There is no reactive component such as capacitance or inductance present to cause a phase shift between the two.

Question 4

Current lags voltage by 90&#65392; in a pure inductive circuit.

Accepted Answer

In a pure inductive circuit, the current lags the voltage by 90 degrees. This means that when the voltage is at its maximum, the current is at its minimum, and vice versa.

Question 5

Inductors are measured in units called the ____.&#10;A) coulomb&#10;B) amp&#10;C) henry&#10;D) ohm

Accepted Answer

Inductors are measured in henrys (H), named after American scientist Joseph Henry who discovered electromagnetic induction independently of Michael Faraday.

Question 6

An inductive circuit contains an inductor or coil as the load instead of a resistor.

Accepted Answer

An inductive circuit does contain an inductor or coil as the load, and not a resistor.

Question 7

Power factor is important because utility companies charge industries large penalties for a poor power factor.

Accepted Answer

This is true. Utility companies charge industries penalties for a poor power factor because it causes inefficiencies in the electrical grid, leading to increased costs for the utility companies to maintain and stabilize the system. A poor power factor also results in wasted energy and increased greenhouse gas emissions. Therefore, maintaining a good power factor is beneficial for both the industry and the environment.

Question 8

VARs is often referred to as ____.&#10;A) apparent power&#10;B) wattless power&#10;C) power factor&#10;D) volt-amps

Accepted Answer

VARs (Volt-Ampere Reactive) is often referred to as wattless power because it represents the reactive power in an AC circuit, which does not perform any work.

Question 9

Reactance is given the electrical symbol ____.&#10;A) F&#10;B) X&#10;C) L&#10;D) ( $\pi$)

Accepted Answer

Reactance is represented by the symbol X in electrical circuits.

Question 10

The simplest of the AC loads is a circuit that contains only pure inductance.

Accepted Answer

The simplest of the AC loads is a resistive circuit because it contains only resistance and does not involve any phase difference between the voltage and current.

Deck 7: Inductance