NASCLA Journeyman Electrician Exam Questions

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121.

Where cable is used in cabinets, what is required of each cable?

  • To be secured to the cabinet

  • To be identified

  • To be free from nicks, cuts, and abrasions

  • To be properly sized

Correct answer: To be secured to the cabinet

In the question, identify wiring methods and materials. This is primarily a method. Then identify cabinet and cable.

These are still primarily methods. Following these three will lead you to your answer.

All other options are true, but are not the correct answer.

122.

Moisture- and heat-resistant thermoplastic is a trade name associated with which types of cable insulation type letters?

  • THHW, THW, THW-2, THWN, THWN-2

  • RHW, RHW-2, TW, XHHW, XHHW-2, XHWN, XHWN-2 

  • RHH, SIS, XHN, XHHN  

  • Z, ZW, ZW-2

Correct answer: THHW, THW, THW-2, THWN, THWN-2

The items to identify here are construction specifications and conductor construction and application. Both these issues would fall under conductors for general wiring.

The question is really about learning to read NEC tables. NEC tables have a trove of information and are clear, but can be easily misread. Answers to many Code issues are only found by referencing the information in multiple tables. If in doubt, double check.

The other options are type letter sets that apply to the trade names Thermoset, Moisture, or Modified Ethylene Tetrafluoroethylene.

123.

What are raceways between cabinets, boxes, fittings, other enclosures, or outlets required to be?

  • Continuous

  • Mechanically sound

  • Well supported

  • Secured where suspended

Correct answer: Continuous

Mechanical continuity is the first need to recognize. This is a general requirement for wiring methods. 

All the other options may address this, but they are not specifically mentioned in the Code. The wording itself is important, as the Code tests will not ask you how you would say it. Many Code test questions will have plausible answers that may sound correct but do not match the wording in the Code.

124.

When considering where a device is located from the prints, what primary dimension are you looking for first?

  • Center or edge

  • Length

  • Height

  • Width

Correct answer: Center or edge

When considering where devices, lighting, or equipment is to be located, determine whether the plans are using measurements taken to or from the center or the edge.

Edge dimensions will have a distinct extension line from the edge to measure from.

Normal devices are most often measured from the center. If necessary, a device will be depicted with a bullseye on the appropriate schedule, denoting common take-off.

125.

Using approved methods, what is required in the opening around all electrical penetrations into or through fire-resistant-rated walls, partitions, ceilings or floors?

  • Fire resistance rating

  • Structural integrity

  • Fire prevention measures

  • Fireproof rating

Correct answer: Fire resistance rating

We often think of this in terms of fire prevention, proof, rating, or resistance. The Code subtitle or issue to think about is the spread of fire and products of combustion. The answer to this question falls under the general requirements for wiring.

As this question is addressed under spread of fire, we can see the perspective from which the Code addresses issues at times. It is learning and understanding these perspectives that will help you find the Code answers. It is more about learning a thought process through the Code than memorization.

The other options are things we say regarding electrical penetrations and may be synonymous, but do not satisfy the Code answer. 

126.

In electric ranges and dryers where a single conductor is allowed to be used for both equipment grounding and the unbalanced load, what is this conductor considered?

  • A current-carrying conductor

  • An ungrounded conductor

  • A grounded conductor 

  • A grounding conductor

Correct answer: A current-carrying conductor

This is addressed under ampacity tables concerning the ampacities for flex cable, which is equipment for general use.

Here, we have ampacities for current-carrying conditions considered beyond the ampacity considerations under conductors for general wiring. These are general considerations of neutrals specifically addressed in several ways in Article 400.5(A). 

This is specifically provided for at times under 250.140. Verify these provisions and allowances carefully to ensure they apply.

The other options are how conductors are addressed, but not specifically here.

127.

An arc flash hazard is a source of possible injury or damage to health associated with what?

  • The release of energy caused by an electric arc

  • The explosion caused by a sudden release of electricity

  • The release of electrical energy from its intended path

  • The release of energy caused by a sudden electrical discharge

Correct answer: The release of energy caused by an electric arc

The question and answer together are the definition of an arc flash hazard as specified by the NFPA. It is the energy of electricity that causes the damage here. This is what all electrical safety and all LOTO measures are intended to prevent: the unexpected, sudden release of energy. This will happen at times without warning. In almost all cases, there is clear evidence that someone made a preventable mistake that caused the hazard. Things don’t blow up by themselves.

Often, it was an error made some time ago, such as leaving a nut or bolt in the top of a panel that was later unseen and fell onto the bus. The fire marshalls often find evidence for this type of example. There are many other reasons, all with the same ending: a ball of fire 5 feet in diameter reaching instantaneous temperatures as hot as the sun, but thousands of degrees for the several seconds these can last.

This ball of fire is led by liquid copper or aluminum nearly instantaneously hitting its melting point at 800-1100 degrees. The amperage and voltages make the windows of the melting point lower than the actual melting point of the metals. These blasts are rarely survivable.

Common electrical short circuits are mini arc blasts. Burns or flying copper and aluminum slag injuries need immediate medical attention.

If a person is 5-25 feet from this blast, it is common for the skin to quickly turn red (thus, the 25-foot boundary rule). Electricians affectionately call this sunburn. It needs immediate medical attention.

The other answers are descriptive, but fail to accurately define an arc flash hazard.

128.

Article 502 covers the requirements for electrical and electronic equipment and wiring for all voltages in Class II, Div. 1 and 2 locations where:

  • Fire or explosion hazards may exist due to combustible dust

  • Fire or explosion hazards may exist due to flammable gases

  • Fire or explosion hazards may exist due to flammable liquids

  • Fire or explosion hazards may exist due to combustible materials

Correct answer: Fire or explosion hazards may exist due to combustible dust

Class II, Div. 1 and 2 locations are defined in 500.5(C) as "hazardous because of the presence of combustible dust". These locations are separated into three groups as provided in 500.6(B). Two types of dust environments typically warrant a Class II, Div. 1 area classification:

  • First, where a cloud of combustible dust is likely to be present continually or intermittently under normal operating conditions, including repair, maintenance, or leakage.
  • Second, generally, where more than 1/8" of combustible dust may accumulate in a 24-hour period.

129.

Positively charged objects have outward-going lines of force while negatively charged objects have in-ward lines of force. What will these lines of force never do?

  • Cross each other

  • Aline

  • Co-inside

  • Reverse

Correct answer: Cross each other

This is due to the law of charges: opposite charges attract and like charges repel. These lines do connect at the ends of opposite charged electrons, but never cross. These charges, forces, and/or actions are involved in all forms of electricity. 

These lines of force create and/or are involved in magnetism, inductance, eddy currents, and other issues where current lines may and do cross. Electricians must understand how these build on each other to provide safe electrical installations.

130.

A communications circuit extends service from the communications utility or service provider up to where?

  • And including the customer's communications equipment

  • The customer's point of entrance

  • But excluding the customer's communications equipment

  • The customer's block

Correct answer: And including the customer's communications equipment

This is the NEC definition. The communications circuit does include the customer's communications equipment.

The other options are other borderlines.

131.

Provided with a means to permit circulation of air sufficient to remove an excess of heat, fumes, or vapors is known as what?

  • Ventilated

  • Plenum

  • Combustible gas detection system

  • Free air

Correct answer: Ventilated

Ventilated is only a small part of the requirements for providing electrical installations that are free from hazards in hazardous locations. There are many components to evaluating hazardous locations. Cover all the bases.

The other options are incorrect or defined separately. If you do not know them, review them.

132.

A dangerous condition such that contact or equipment failure can result in electric shock, arc flash burn, thermal burn, or arc blast injury is known as what?

  • Electrical hazard

  • Energized

  • Working on

  • Risk

Correct answer: Electrical hazard

The question is the NFPA definition of electrical hazard and what electricians’ risk when working on energized parts. When anyone comes into contact with energized parts, this voltage source presents a likelihood that an injury could occur. Learn to identify electrical hazards to reduce the risks associated with those hazards.

The other options are closely related. See definitions of other options in NFPA 70E for further review. The differences will help with testing and application.

133.

What is the correct term for opposition to current in an ac system?

  • Impedance

  • Resistance

  • Inductive reactance

  • Capacitive reactance

Correct answer: Impedance

In a dc circuit, resistance is the total opposition to current. This term is often applied to ac circuits as well, but is only one part of the total equation.

The total opposition to current in an ac system is impedance.

Impedance consists of three things:

  • Resistance
  • Inductive reactance
  • Capacitive reactance

All three offer opposition to current in an ac system. Impedance is measured in ohms.

See Soares definitions for more information.

The other options are related to opposition of current, but are incorrect.

134.

The branch circuits you have run were calculated on the basis of volt-amperes per square meter. This wiring system provided up to and including this panelboard, will serve the calculated load.

Within the panel, how are you required to distribute the circuits?

  • Evenly proportional among multi-outlet branch circuits

  • Within percentages of appliances and dedicated circuits

  • Apply the 80% rule to all circuits

  • Calculate appliance loads and evenly distribute other branch circuits

Correct answer: Evenly proportional among multi-outlet branch circuits

This is a basic branch circuit requirement and is a soft way of calculating loads. Homes or facilities that are partially unfinished may apply this method. Generally, more specific methods of load balancing are implemented. But where the sq/ft (or meter) method is used, evenly distribute the loads.

The other options are questions/answers or parts of general load calculations.

135.

You are installing a branch circuit supplying both continuous and noncontinuous loads. Some appliances are on this circuit. Overcurrent protection is required on these circuits.

The rating of your overcurrent device is required to be at least that of the noncontinuous load plus what percent of the continuous load?

  • 125%

  • 80%

  • A factor of 1.73

  • 85%

Correct answer: 125%

Branch circuits, overcurrent protection, and continuous and noncontinuous loads are your indicators. Researching these in the Code will get you to your answer. Here, the 125% general factor for circuits, ampacities, and loads is found. 

Appliances are not relevant to finding your answer. A few Code test questions have been known to have information in them that is not needed to answer the question. This reflects real life. On the jobsite, a lot of information is flying around. What do you need to know when? What applies and what doesn't?

The other options are random demand factors for other calculations. 1.73 is a constant for transformer and phase to phase calculations. Remember 1.73, we use it inversely for different calculations.

136.

You are installing underground cables and conductors over which a building will be erected. Which of the following details the minimum requirement(s)?    

  • Shall be in a raceway

  • Shall be in a raceway or rated direct burial

  • Shall be either in a raceway or rated direct burial, encased in concrete

  • Shall be buried above underground water or sewer lines

Correct answer: Shall be in a raceway

The question concerns the minimum or general requirements for wiring methods in underground installations that are under buildings. The focus of the question is about the method of installation. Reading the questions, learn to see these things. Code questions are about learning to see real-life field situations in terms of the Code and knowing what it is the Code may require.

Anything under a building must be in a raceway. 

Direct burial cable cannot be the sole protection under a building. Ground settlement is probably the reason. The Code mentions ground settlement considerations elsewhere, but does not give a specific reason here. Commercial cable companies may get away with this, but they are communication cables with very low voltage.

Concrete is a common practice and at times a requirement elsewhere, but not a general requirement of the Code. 

Water and sewer considerations are made and there may be locality requirements, but not in or of the general NEC requirements.

137.

What is the primary difference between scientific and engineering notation?

  • Steps of 10 vs. 1000

  • Steps of 100 vs. 10

  • European vs. U.S. standards

  • SI vs. ANSI

Correct answer: Steps of 10 vs. 1000

Metric prefixes are used in the electrical field because it is based on science. Electricians do use standard metric prefixes: Pico, Nano, Micro, etc. However, electricians often follow the engineering notations which are in steps of 1000 vs. the scientific steps of 10.

138.

What does a capacitor store?

  • Electrical stress

  • Voltage

  • Current

  • Resistance

Correct answer: Electrical stress

A capacitor stores electrical stress. This amounts to capacitive reactance which opposes current due to capacitance of the circuit.

The IEEE definition of capacitance is the property of systems of conductors and dielectrics which permits the storage of electricity when potential difference exists between the conductors.

The conductors of a circuit are collectively fighting to both allow the flow and the storage of electricity at the same time.

The other answers are components of electrical stress.

139.

How do you calculate area?

  • A = L x W

  • V = L x W x H

  • C = π  x radius2

  • V = π x r2 x H

Correct answer: A = L x W

Area = Length x Width

This is useful in numerous applications on the jobsite. Lighting area requirements are based on square footage of areas to be illuminated.

Basic construction calculations are abundant on the web. Brush up on them as needed.

The other options are the area of a circle, and the volume of a cube and cylinder.

140.

Which of the following is equipment sealed against the entrance of an external atmosphere where the seal is made by fusion; for example, soldering, brazing, welding, or the fusion of glass to metal?

  • Hermetically sealed

  • Dusttight

  • Explosionproof equipment

  • Dust-ignitionproof

Correct answer: Hermetically sealed

The is the NEC definition of hermetically sealed.

Hazardous locations have related definitions that are not hard to learn. There are identifiers within them that, once recognized, will help you find the answers in a short amount of time.

It’s about identification, not memorization.

Other options are defined separately. If you do not know them, review them.