AZ C-11 Electrical Contractor Exam Questions
and Correct Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant Download Pdf
1. What is the primary function of a circuit breaker in an electrical
circuit?
a. To increase the circuit voltage
b. To regulate the frequency of the current
c. To protect conductors against overcurrent
d. To improve the power factor
Rationale: A circuit breaker is an overcurrent protective device
designed to interrupt current when it exceeds its rated capacity under
specified conditions. It helps protect conductors and equipment from
damage caused by overloads and short circuits. It is not primarily
intended to regulate voltage, frequency, or power factor.
2. What is the standard unit of electrical resistance?
a. Ampere
,b. Volt
c. Watt
d. Ohm
Rationale: Electrical resistance is measured in ohms (Ω). Resistance
describes how strongly a material opposes the flow of electric current.
Amperes measure current, volts measure electrical potential
difference, and watts measure power.
3. According to Ohm’s law, what current flows through a 12-ohm
resistor connected to a 120-volt source?
a. 5 amperes
b. 10 amperes
c. 12 amperes
d. 20 amperes
Rationale: Ohm’s law states that current equals voltage divided by
resistance: I = V ÷ R. Therefore, 120 ÷ 12 = 10 amperes. This calculation
assumes an ideal source and a purely resistive load.
4. What is the primary purpose of an equipment grounding conductor
(EGC)?
a. To carry normal return current
,b. To increase the available circuit voltage
c. To provide a low-impedance path for fault current
d. To replace the circuit neutral
Rationale: An equipment grounding conductor connects non-current-
carrying metal parts to the grounding and bonding system. During a
ground fault, it provides a low-impedance path that helps operate the
overcurrent protective device. It is not intended to carry normal load
current and cannot generally replace the neutral conductor.
5. Which electrical quantity is measured in amperes?
a. Resistance
b. Power
c. Voltage
d. Current
Rationale: The ampere is the unit of electric current and represents
the rate of flow of electric charge. Voltage is measured in volts,
resistance in ohms, and electrical power in watts.
6. A 240-volt load draws 15 amperes. What is its electrical input
power if the load is purely resistive?
a. 1,600 watts
, b. 2,400 watts
c. 3,600 watts
d. 4,800 watts
Rationale: For a purely resistive load, power is calculated using P = V ×
I. Thus, 240 × 15 = 3,600 watts, or 3.6 kilowatts. For AC loads with a
non-unity power factor, real power also depends on the power factor.
7. What is the principal purpose of a building’s main bonding jumper?
a. To increase the grounding electrode resistance
b. To isolate the service neutral from the equipment grounding system
c. To connect the grounded conductor to the equipment grounding
system at the service
d. To provide a separate neutral for every branch circuit
Rationale: At service equipment, the main bonding jumper establishes
the required connection between the grounded service conductor and
the equipment grounding system. This connection helps ensure that
ground-fault current has an effective return path to the source.
Downstream of the service disconnect, neutral and equipment
grounding conductors generally must remain separated, subject to
applicable code provisions.
and Correct Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant Download Pdf
1. What is the primary function of a circuit breaker in an electrical
circuit?
a. To increase the circuit voltage
b. To regulate the frequency of the current
c. To protect conductors against overcurrent
d. To improve the power factor
Rationale: A circuit breaker is an overcurrent protective device
designed to interrupt current when it exceeds its rated capacity under
specified conditions. It helps protect conductors and equipment from
damage caused by overloads and short circuits. It is not primarily
intended to regulate voltage, frequency, or power factor.
2. What is the standard unit of electrical resistance?
a. Ampere
,b. Volt
c. Watt
d. Ohm
Rationale: Electrical resistance is measured in ohms (Ω). Resistance
describes how strongly a material opposes the flow of electric current.
Amperes measure current, volts measure electrical potential
difference, and watts measure power.
3. According to Ohm’s law, what current flows through a 12-ohm
resistor connected to a 120-volt source?
a. 5 amperes
b. 10 amperes
c. 12 amperes
d. 20 amperes
Rationale: Ohm’s law states that current equals voltage divided by
resistance: I = V ÷ R. Therefore, 120 ÷ 12 = 10 amperes. This calculation
assumes an ideal source and a purely resistive load.
4. What is the primary purpose of an equipment grounding conductor
(EGC)?
a. To carry normal return current
,b. To increase the available circuit voltage
c. To provide a low-impedance path for fault current
d. To replace the circuit neutral
Rationale: An equipment grounding conductor connects non-current-
carrying metal parts to the grounding and bonding system. During a
ground fault, it provides a low-impedance path that helps operate the
overcurrent protective device. It is not intended to carry normal load
current and cannot generally replace the neutral conductor.
5. Which electrical quantity is measured in amperes?
a. Resistance
b. Power
c. Voltage
d. Current
Rationale: The ampere is the unit of electric current and represents
the rate of flow of electric charge. Voltage is measured in volts,
resistance in ohms, and electrical power in watts.
6. A 240-volt load draws 15 amperes. What is its electrical input
power if the load is purely resistive?
a. 1,600 watts
, b. 2,400 watts
c. 3,600 watts
d. 4,800 watts
Rationale: For a purely resistive load, power is calculated using P = V ×
I. Thus, 240 × 15 = 3,600 watts, or 3.6 kilowatts. For AC loads with a
non-unity power factor, real power also depends on the power factor.
7. What is the principal purpose of a building’s main bonding jumper?
a. To increase the grounding electrode resistance
b. To isolate the service neutral from the equipment grounding system
c. To connect the grounded conductor to the equipment grounding
system at the service
d. To provide a separate neutral for every branch circuit
Rationale: At service equipment, the main bonding jumper establishes
the required connection between the grounded service conductor and
the equipment grounding system. This connection helps ensure that
ground-fault current has an effective return path to the source.
Downstream of the service disconnect, neutral and equipment
grounding conductors generally must remain separated, subject to
applicable code provisions.
