Electrical Contractor Electrical Theory & Fundamentals

Question 1

What is the relationship between voltage, current, and resistance?

Accepted Answer

Voltage equals current multiplied by resistance.

Answer

Voltage is the flow of electric charge.

Answer

Current equals resistance multiplied by voltage.

Answer

Resistance is equal to the sum of voltage and current.

Question 2

What is the unit of electrical resistance?

Accepted Answer

Ohms.

Answer

Volts

Answer

Amperes

Answer

Watts

Question 3

Which of the following best describes an electrical circuit?

Accepted Answer

A path that allows current to flow from a power source to a load and back to the source.

Answer

A series of connected electrical components without any power source.

Answer

A device that stores electrical energy.

Answer

An open wire that conducts electricity.

Question 4

What is the purpose of a capacitor in an electrical circuit?

Accepted Answer

To store and release electrical energy.

Answer

To convert DC to AC.

Answer

To provide a constant current supply.

Answer

To increase the frequency of electrical signals.

Question 5

What is the function of an inductor in a circuit?

Accepted Answer

To resist changes in current and store energy in a magnetic field.

Answer

To store energy in an electric field.

Answer

To increase the resistance of the circuit.

Answer

To convert electrical energy to mechanical energy.

Question 6

What is the purpose of a transformer in an electrical circuit?

Accepted Answer

To change the voltage level in an AC circuit.

Answer

To store energy.

Answer

To convert AC to DC.

Answer

To regulate current flow in a circuit.

Question 7

Which of the following describes the power factor of an electrical circuit?

Accepted Answer

The ratio of real power to apparent power.

Answer

The ratio of voltage to current.

Answer

The total amount of current in a circuit.

Answer

The efficiency of energy conversion.

Question 8

What is the main difference between alternating current (AC) and direct current (DC)?

Accepted Answer

DC flows in one direction, while AC changes direction periodically.

Answer

AC flows in one direction, while DC changes direction periodically.

Answer

AC is used in batteries, while DC is used in power lines.

Answer

There is no difference between AC and DC.

Question 9

Which of the following is the unit of electrical power?

Accepted Answer

Watts.

Answer

Amperes

Answer

Volts

Answer

Ohms