IEC - Independent Electrical Contractors Electrical Theory and Principles Questions and Answers

Question 1

An AC circuit contains a resistor, an inductor, and a capacitor. What is the total opposition to the flow of alternating current called?

Accepted Answer

Impedance

Answer

Reactance

Answer

Resistance

Answer

Admittance

Question 2

A simple circuit has a voltage of 120V and a resistance of 10 ohms. According to Ohm's Law, what is the current flowing through the circuit?

Accepted Answer

12 Amperes

Answer

1200 Amperes

Answer

12 Volts

Answer

0.083 Amperes

Question 3

A standard 120V AC outlet in the United States provides a voltage that is typically specified as its RMS value. What does the RMS (Root Mean Square) value represent?

Accepted Answer

The equivalent DC voltage that would produce the same heating effect.

Answer

The peak voltage of the AC waveform.

Answer

The average voltage over one full cycle.

Answer

The instantaneous voltage at any point in time.

Question 4

An electrician is running two copper conductors of the same length to a load. Conductor A has a cross-sectional area of 10.4 mm², and Conductor B has a cross-sectional area of 5.2 mm². Which of the following statements is true?

Accepted Answer

Conductor B has twice the resistance of Conductor A.

Answer

Conductor A has twice the resistance of Conductor B.

Answer

Both conductors have the same resistance.

Answer

Conductor B has half the resistance of Conductor A.

Question 5

In a parallel circuit containing three resistors of 10Ω, 20Ω, and 40Ω, what can be said about the total resistance of the circuit?

Accepted Answer

It is less than the smallest individual resistance (10Ω).

Answer

It is equal to the sum of the individual resistances (70Ω).

Answer

It is equal to the average of the resistances (23.3Ω).

Answer

It is greater than the largest individual resistance (40Ω).

Question 6

A motor is operating on a 240V circuit and is drawing a current of 5A. What is the power consumed by the motor?

Accepted Answer

1200 Watts

Answer

48 Watts

Answer

245 Watts

Answer

0.021 Watts