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New Mexico Low Voltage Practice study materials
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New Mexico Low Voltage Practice practice questions

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Question 1General Electrical Knowledge and Theory

A low-voltage technician is calculating the resistance of a copper conductor. Which relationship correctly expresses Ohm's law for finding resistance?

  1. R = V / I Correct answer.
  2. R = V × I
  3. R = I² × V
  4. R = I / V

Explanation

Ohm's law states that current is directly proportional to voltage and inversely proportional to resistance, so V = I × R. Rearranging that equation to solve for resistance gives R = V / I. The other forms misplace the terms and do not follow from the original relationship.

Question 2General Electrical Knowledge and Theory

A circuit draws 2 amperes at 12 volts. What power does the circuit dissipate?

  1. 144 watts
  2. 6 watts
  3. 0.167 watts
  4. 24 watts Correct answer.

Explanation

Electrical power equals voltage multiplied by current, so 12 V × 2 A = 24 W. This is the standard power equation used to size conductors and equipment. The other values come from dividing or squaring the given quantities incorrectly.

Question 3General Electrical Knowledge and Theory

In a series circuit containing three resistors, which statement about current is true?

  1. The same current flows through every resistor. Correct answer.
  2. Current is highest through the largest resistor.
  3. Current splits proportionally to resistance at each resistor.
  4. Current is zero between the first and second resistor.

Explanation

A series circuit provides only one path for electron flow, so the same current passes through each element in turn. Voltage divides across the resistors, but current does not. Splitting current occurs only in parallel branches.

Question 4General Electrical Knowledge and Theory

Two identical 100-ohm resistors are connected in parallel. What is the total equivalent resistance?

  1. 25 ohms
  2. 200 ohms
  3. 50 ohms Correct answer.
  4. 100 ohms

Explanation

For two equal resistors in parallel, the equivalent resistance is half of one resistor's value, so 100 / 2 = 50 ohms. The general formula 1/RT = 1/R1 + 1/R2 confirms this result. Parallel resistance is always less than the smallest individual resistor.

Question 5General Electrical Knowledge and Theory

Which material is classified as a semiconductor commonly used in low-voltage devices?

  1. Rubber
  2. Copper
  3. Glass
  4. Silicon Correct answer.

Explanation

Silicon is a semiconductor whose conductivity falls between that of conductors and insulators, which makes it the basis for diodes and transistors. Copper is a good conductor, while rubber and glass are insulators. Semiconductor behavior is what enables controlled switching in low-voltage electronics.

Question 6General Electrical Knowledge and Theory

What is the frequency of an alternating current that completes 60 full cycles in one second?

  1. 60 hertz Correct answer.
  2. 120 hertz
  3. 30 hertz
  4. 3600 hertz

Explanation

Frequency in hertz equals the number of complete cycles per second, so 60 cycles in one second is 60 Hz. This is the standard power-line frequency in North America. Multiplying or dividing the cycle count does not change the definition of frequency.

Question 7General Electrical Knowledge and Theory

Which unit is used to express electrical resistance?

  1. Volt
  2. Ampere
  3. Ohm Correct answer.
  4. Watt

Explanation

Resistance is measured in ohms, symbolized by the Greek letter omega. One ohm is the resistance that allows one ampere to flow when one volt is applied. Volts measure potential difference, amperes measure current, and watts measure power.

Question 8General Electrical Knowledge and Theory

A low-voltage cable carries 1.5 amperes continuously. Using the common 3-ampere-per-square-millimeter rule of thumb for copper, what minimum conductor cross-section is indicated?

  1. 1.5 square millimeters
  2. 4.5 square millimeters
  3. 3.0 square millimeters
  4. 0.5 square millimeters Correct answer.

Explanation

Dividing the continuous current by the current density gives 1.5 A / 3 A per mm² = 0.5 mm². This rule of thumb provides a starting point before applying any code ampacity tables. Selecting a larger standard size is permitted, but the minimum computed value is 0.5 mm².

Question 9General Electrical Knowledge and Theory

In a parallel circuit with two branches, one drawing 3 amperes and the other drawing 5 amperes, what current flows in the main feeder?

  1. 3.75 amperes
  2. 15 amperes
  3. 2 amperes
  4. 8 amperes Correct answer.

Explanation

Kirchhoff's current law states that the total current entering a junction equals the sum of the branch currents leaving it. Adding the two branch currents gives 3 A + 5 A = 8 A in the main feeder. Subtracting or multiplying branch currents does not satisfy conservation of charge.

Question 10General Electrical Knowledge and Theory

A 120-volt circuit has a total resistance of 40 ohms. What current flows?

  1. 3 amperes Correct answer.
  2. 0.33 amperes
  3. 4800 amperes
  4. 160 amperes

Explanation

Applying Ohm's law, current equals voltage divided by resistance: 120 V / 40 ohms = 3 A. This is the fundamental relationship used to predict current in a resistive circuit. Multiplying the values instead of dividing produces an unrelated figure.

Question 11General Electrical Knowledge and Theory

Which effect describes the voltage induced in a conductor when it experiences a changing magnetic field?

  1. Inductive reactance
  2. Electromagnetic induction Correct answer.
  3. Capacitive coupling
  4. Dielectric absorption

Explanation

Electromagnetic induction is the generation of a voltage in a conductor by a changing magnetic field, as described by Faraday's law. This principle underlies transformers and generators used throughout low-voltage systems. Reactance and coupling are related concepts but do not define the induction effect itself.

Question 12General Electrical Knowledge and Theory

A transformer has 200 turns on its primary and 50 turns on its secondary. If the primary is supplied at 120 volts, what is the secondary voltage?

  1. 30 volts Correct answer.
  2. 480 volts
  3. 60 volts
  4. 24 volts

Explanation

The turns ratio is 200:50, or 4:1. Secondary voltage equals primary voltage divided by the turns ratio: 120 V / 4 = 30 V. A step-down transformer reduces voltage in proportion to the reduction in turns.

Question 13General Electrical Knowledge and Theory

What distinguishes alternating current from direct current in a low-voltage system?

  1. AC periodically reverses direction. Correct answer.
  2. AC flows in one direction only.
  3. DC reverses direction periodically.
  4. DC always has a higher voltage.

Explanation

Alternating current periodically reverses its direction of flow, while direct current maintains a constant polarity. This reversal is what gives AC its characteristic frequency. Voltage magnitude does not determine whether current is AC or DC.

Question 14General Electrical Knowledge and Theory

A 12-volt battery is connected across a 6-ohm resistor. How much power is converted to heat?

  1. 0.5 watts
  2. 72 watts
  3. 2 watts
  4. 24 watts Correct answer.

Explanation

Power can be found as V² / R: (12 V)² / 6 ohms = 144 / 6 = 24 W. Alternatively, current is 2 A and power is 12 V × 2 A = 24 W. Both approaches confirm the same result.

Question 15General Electrical Knowledge and Theory

Which statement correctly describes the voltage across each branch of a parallel circuit?

  1. It equals the source voltage across every branch. Correct answer.
  2. It is divided equally among the branches.
  3. It is zero in the branch with the highest resistance.
  4. It decreases with each additional branch.

Explanation

In a parallel circuit, each branch connects directly across the source, so the full source voltage appears across every branch. Current divides among the branches, but voltage does not. This is why parallel wiring is used for receptacles and loads.

Question 16General Electrical Knowledge and Theory

A technician measures 0.05 amperes through a 2,000-ohm resistor. What voltage drop appears across it?

  1. 0.25 volts
  2. 40,000 volts
  3. 0.000025 volts
  4. 100 volts Correct answer.

Explanation

Ohm's law gives voltage as current times resistance: 0.05 A × 2,000 ohms = 100 V. Multiplying these quantities yields the potential difference across the resistor. Dividing or squaring the values produces unrelated results.

Question 17General Electrical Knowledge and Theory

Why are standard electrical formulas expressed in consistent base units before calculation?

  1. To eliminate the need for measurement
  2. To increase the current in the circuit
  3. To ensure the resulting value carries the correct unit Correct answer.
  4. To convert all results into watts

Explanation

When quantities are expressed in base units such as volts, amperes, and ohms, the arithmetic produces a result in the expected unit. Mixing prefixes like milliamperes without conversion leads to errors of a factor of 1,000. Unit consistency is a safeguard for calculation accuracy.

Question 18General Electrical Knowledge and Theory

A 24-volt control circuit must operate a device drawing 0.4 amperes. What resistance does the device present?

  1. 0.0167 ohms
  2. 60 ohms Correct answer.
  3. 96 ohms
  4. 9.6 ohms

Explanation

Resistance equals voltage divided by current: 24 V / 0.4 A = 60 ohms. This follows directly from rearranging Ohm's law. Multiplying the values instead of dividing gives an incorrect result.

Question 19General Electrical Knowledge and Theory

A resistor has color bands brown, black, red, and gold. What is its nominal value and tolerance?

  1. 10 ohms, ±5%
  2. 1,000 ohms, ±10%
  3. 100 ohms, ±10%
  4. 1,000 ohms, ±5% Correct answer.

Explanation

Brown represents 1, black represents 0, and red as a multiplier means two additional zeros, giving 1,000 ohms. Gold in the tolerance band indicates plus or minus 5 percent. Reading the multiplier band as a digit or misreading the tolerance produces the other choices.

Question 20General Electrical Knowledge and Theory

In a series circuit of 10 ohms and 20 ohms across a 30-volt source, what is the voltage drop across the 20-ohm resistor?

  1. 20 volts Correct answer.
  2. 30 volts
  3. 15 volts
  4. 10 volts

Explanation

Total resistance is 30 ohms, so current is 30 V / 30 ohms = 1 A. The drop across the 20-ohm resistor is 1 A × 20 ohms = 20 V. Voltage divides in proportion to resistance in a series circuit.

Question 21General Electrical Knowledge and Theory

A circuit has a 0.25-henry inductor operating at 60 hertz. What is its inductive reactance?

  1. 94.2 ohms Correct answer.
  2. 150 ohms
  3. 15 ohms
  4. 0.0042 ohms

Explanation

Inductive reactance is XL = 2πfL. Substituting gives 2 × 3.1416 × 60 × 0.25, which equals approximately 94.2 ohms. Reactance rises with both frequency and inductance, so the result must exceed the simple product of frequency and inductance only slightly.

Question 22General Electrical Knowledge and Theory

A technician needs 8 amperes at 5 volts from a 20-volt source. Which transformer turns ratio is required?

  1. 5:1 step-down
  2. 2:1 step-down
  3. 1:4 step-up
  4. 4:1 step-down Correct answer.

Explanation

The voltage ratio is 20 V to 5 V, or 4:1, so a step-down transformer with a 4:1 turns ratio is needed. In an ideal transformer, current rises in inverse proportion to voltage, so the secondary can deliver the higher current. Other ratios would produce the wrong secondary voltage.

Question 23General Electrical Knowledge and Theory

Two resistors of 30 ohms and 60 ohms are connected in parallel across a 60-volt source. What total current does the source supply?

  1. 2 amperes
  2. 3 amperes Correct answer.
  3. 0.67 amperes
  4. 90 amperes

Explanation

Equivalent resistance is (30 × 60) / (30 + 60) = 20 ohms. Total current is 60 V / 20 ohms = 3 A, which also equals the sum of branch currents of 2 A and 1 A. Summing branch currents confirms the result.

Question 24General Electrical Knowledge and Theory

A conductor carries 4 amperes and has a resistance of 0.5 ohms per 100 meters over a 50-meter run. What power is lost in the conductor?

  1. 8 watts
  2. 4 watts
  3. 16 watts
  4. 2 watts Correct answer.

Explanation

The run resistance is 0.5 ohms × (50/100) = 0.25 ohms. Conductor power loss is I²R = 4² × 0.25 = 16 × 0.25 = 4 W... correcting the arithmetic, the loss is 4 watts. Verifying with I²R gives 16 × 0.25 = 4 W.

Question 25General Electrical Knowledge and Theory

A capacitor and an inductor are both present in an AC circuit. How do their reactances respond as frequency increases?

  1. Both reactances decrease.
  2. Both reactances increase.
  3. Capacitive reactance increases while inductive reactance decreases.
  4. Capacitive reactance decreases while inductive reactance increases. Correct answer.

Explanation

Capacitive reactance is inversely proportional to frequency, so it falls as frequency rises. Inductive reactance is directly proportional to frequency, so it rises. The two components therefore respond in opposite directions to a frequency change.

Question 26General Electrical Knowledge and Theory

A low-voltage technician is sizing a conductor and wants to compare the cross-sectional area of two wires. Which unit expresses the cross-sectional area of a conductor?

  1. Ohm
  2. Henry
  3. Circular mil Correct answer.
  4. Watt

Explanation

Conductor cross-sectional area is conventionally measured in circular mils, where one circular mil is the area of a circle one thousandth of an inch in diameter. This unit lets a technician compare wire sizes directly without converting to square inches. Ohms, watts, and henries describe other electrical quantities entirely.

Question 27General Electrical Knowledge and Theory

In a low-voltage DC circuit, what is the relationship between current, voltage, and resistance described by Ohm's law?

  1. Current equals power divided by resistance
  2. Current equals resistance divided by voltage
  3. Current equals voltage multiplied by resistance
  4. Current equals voltage divided by resistance Correct answer.

Explanation

Ohm's law states that current through a resistive element equals the voltage across it divided by its resistance, written I = V/R. This means current rises with voltage and falls as resistance increases. The other arrangements invert or confuse the relationship and do not describe Ohm's law.

Question 28General Electrical Knowledge and Theory

A low-voltage installer needs to know the conventional direction of current flow in a metallic conductor. Which statement describes conventional current?

  1. It alternates direction once per second in a DC circuit
  2. It flows from the positive terminal to the negative terminal through the external circuit Correct answer.
  3. It flows only inside the conductor's insulation
  4. It flows from the negative terminal to the positive terminal through the external circuit

Explanation

Conventional current is defined as flowing from the positive terminal through the external circuit to the negative terminal. Actual electron flow moves in the opposite direction, but circuit analysis and most formulas use the conventional definition. This convention keeps sign conventions consistent in calculations.

Question 29General Electrical Knowledge and Theory

A low-voltage control transformer steps 120 volts down to 24 volts. If it delivers 2 amperes on the secondary, approximately what current flows in the primary, assuming an ideal transformer?

  1. 240 amperes
  2. 2 amperes
  3. 0.4 amperes Correct answer.
  4. 10 amperes

Explanation

In an ideal transformer, power in equals power out, so primary current equals secondary power divided by primary voltage. Secondary power is 24 volts times 2 amperes, or 48 volt-amperes. Dividing 48 volt-amperes by 120 volts gives 0.4 amperes in the primary.

Question 30General Electrical Knowledge and Theory

A low-voltage circuit has a 48-ohm resistor carrying 0.25 amperes. What voltage drop appears across the resistor?

  1. 192 volts
  2. 0.005 volts
  3. 12 volts Correct answer.
  4. 48 volts

Explanation

Ohm's law gives voltage as current times resistance. Multiplying 0.25 amperes by 48 ohms yields 12 volts. This is a routine application of V = IR when current and resistance are both known.

Question 31General Electrical Knowledge and Theory

A low-voltage technician measures a 0.5-ampere current through a resistive load and finds 6 volts across it. What power does the load dissipate?

  1. 0.083 watts
  2. 12 watts
  3. 6 watts
  4. 3 watts Correct answer.

Explanation

Electrical power equals voltage times current, P = VI. Multiplying 6 volts by 0.5 amperes gives 3 watts. This relationship applies to resistive loads and is fundamental to sizing components and checking heat generation.

Question 32General Electrical Knowledge and Theory

Two resistors, 40 ohms and 60 ohms, are connected in parallel across a 120-volt source. What current flows through the 40-ohm branch?

  1. 2 amperes
  2. 1.2 amperes
  3. 3 amperes Correct answer.
  4. 5 amperes

Explanation

In a parallel circuit the full source voltage appears across each branch. Applying Ohm's law to the 40-ohm branch gives 120 volts divided by 40 ohms, or 3 amperes. The other branch draws 2 amperes, and the total is 5 amperes, but the question asks only about the 40-ohm branch.

Question 33General Electrical Knowledge and Theory

A low-voltage cable run must supply a 12-volt load drawing 1.5 amperes over a distance where the conductor resistance totals 0.4 ohms one way. What is the approximate voltage drop in the circuit?

  1. 0.3 volts
  2. 0.9 volts
  3. 1.2 volts Correct answer.
  4. 0.6 volts

Explanation

Voltage drop equals current times the total conductor resistance in the complete loop. Current must travel out and back, so the loop resistance is twice the one-way value, or 0.8 ohms. Multiplying 1.5 amperes by 0.8 ohms gives 1.2 volts of drop.

Question 34General Electrical Knowledge and Theory

In a series circuit containing a 10-ohm resistor and a 30-ohm resistor across a 40-volt source, what is the current through the circuit?

  1. 1 ampere Correct answer.
  2. 0.75 ampere
  3. 1.33 amperes
  4. 4 amperes

Explanation

In a series circuit the resistances add, giving a total of 40 ohms. Dividing the 40-volt source by 40 ohms yields 1 ampere, which flows through both resistors. The same current passes through every element in a series circuit.

Question 35General Electrical Knowledge and Theory

A low-voltage technician needs to know how total resistance behaves when additional resistors are added in parallel. Which statement is correct?

  1. Total resistance increases above the largest resistor value
  2. Total resistance is less than the smallest individual resistor value Correct answer.
  3. Total resistance is always the sum of all resistor values
  4. Total resistance equals the average of the resistor values

Explanation

Each parallel branch provides an additional path for current, so total resistance is always smaller than the smallest branch resistance. The reciprocal formula makes this clear because the conductances add. Adding more parallel branches further reduces total resistance.

Question 36General Electrical Knowledge and Theory

A low-voltage installer is choosing insulation for a conductor run. Which property of the insulation determines the maximum voltage the cable may safely withstand?

  1. Inductance per meter
  2. Resistivity of the copper
  3. Temperature coefficient
  4. Dielectric strength Correct answer.

Explanation

Dielectric strength describes how much voltage an insulating material can withstand per unit thickness before breakdown. It is the key property in selecting insulation for a given circuit voltage. Resistivity and inductance describe the conductor, not the insulation's voltage capability.

Question 37General Electrical Knowledge and Theory

A low-voltage AC circuit contains a capacitor and an inductor in series. How does the net reactance behave as the frequency approaches the resonant frequency?

  1. Net reactance equals the sum of the two reactance magnitudes
  2. Net reactance increases without limit
  3. Net reactance becomes purely resistive and doubles
  4. Net reactance approaches zero because the two reactances cancel Correct answer.

Explanation

Capacitive reactance falls with rising frequency while inductive reactance rises, and they oppose each other in a series circuit. At resonance the two magnitudes are equal, so the net reactance cancels and approaches zero, leaving only resistance. This is why current peaks at resonance.

Question 38General Electrical Knowledge and Theory

A low-voltage system uses a 24-volt AC source. What value most closely represents the peak voltage of this sinusoidal waveform?

  1. 34 volts Correct answer.
  2. 24 volts
  3. 17 volts
  4. 48 volts

Explanation

The stated value of an AC voltage is normally its root-mean-square value. Peak voltage equals RMS voltage times the square root of two, so 24 volts times about 1.414 gives roughly 34 volts. Insulation and component ratings must account for this higher peak.

Question 39General Electrical Knowledge and Theory

A low-voltage technician is troubleshooting a circuit where measured current is far below the value expected from Ohm's law. Which condition most likely explains the discrepancy?

  1. The load resistance is lower than assumed
  2. A poor connection is adding unexpected series resistance Correct answer.
  3. The source voltage is higher than assumed
  4. The conductor gauge is larger than required

Explanation

Lower-than-expected current with a known source voltage points to higher-than-expected resistance in the loop. A loose terminal, corroded splice, or undersized conductor adds series resistance and reduces current. The technician should inspect connections and measure loop resistance before replacing the load.

Question 40General Electrical Knowledge and Theory

A low-voltage circuit contains both a resistive load and an inductor. Which statement correctly compares the phase relationship between voltage and current in the purely inductive portion?

  1. Current lags the voltage by 90 degrees Correct answer.
  2. Current leads the voltage by 90 degrees
  3. Current leads the voltage by 45 degrees
  4. Current is in phase with the voltage

Explanation

In a pure inductance the voltage reaches its maximum before the current does, so current lags voltage by 90 degrees. This phase shift arises because the inductor opposes changes in current. In a capacitor the relationship reverses and current leads voltage.

Question 41Low Voltage Systems and Applications

A technician is installing a Class 2 limited-energy circuit for landscape lighting control. Which characteristic most directly defines a Class 2 circuit under the NEC?

  1. It must be installed in rigid metal conduit for its entire length
  2. It requires a grounded metal enclosure at every splice point
  3. It is permitted to carry line voltage up to 600 volts between conductors
  4. It is limited in power output and rated so that it presents a low fire and shock hazard under normal conditions Correct answer.

Explanation

Class 2 circuits are defined by their power and voltage limitations, which keep energy low enough that fire and electric shock hazards are limited under normal operating conditions. The limits are established by the power source ratings and the circuit classification tables, not by raceway type or grounding of every splice.

Question 42Low Voltage Systems and Applications

Which wiring method is generally permitted for exposed low voltage communications cable run across the ceiling of a finished office area?

  1. Romex sheathed cable fished through the same pathway
  2. Cable laid loosely on top of ceiling tiles without support
  3. Listed plenum-rated cable supported by J-hooks attached to the structure Correct answer.
  4. Non-plenum cable stapled directly to the suspended ceiling grid

Explanation

Communications and low voltage cables must be supported and, in a plenum ceiling, must carry the appropriate plenum listing. J-hooks provide listed support and keep the cable off the ceiling grid and tiles.

Question 43Low Voltage Systems and Applications

A low voltage contractor is pulling Cat 6 cable through a bundle alongside several power circuits. What is the primary reason to maintain separation from the power conductors?

  1. To prevent the data cable from acting as an equipment grounding conductor
  2. To keep the data cable within its listed temperature rating
  3. To reduce electromagnetic interference coupling onto the data cable Correct answer.
  4. To satisfy the ampacity derating rules for power conductors

Explanation

Power conductors produce changing magnetic fields that can induce noise on nearby signal cables, degrading data performance. Maintaining separation is a standard practice to limit that coupling and preserve signal integrity.

Question 44Low Voltage Systems and Applications

Which cable rating indicates a cable suitable for installation in a space used as a return air plenum?

  1. CMP Correct answer.
  2. CMG
  3. CMR
  4. CMX

Explanation

The CMP designation identifies communications plenum cable, which is listed for use in ducts, plenums, and other air-handling spaces because of its low smoke and flame characteristics. The other suffixes denote riser, general-purpose, and limited-use ratings.

Question 45Low Voltage Systems and Applications

A technician is terminating a 66 block for a voice distribution frame. Which termination method does this block use?

  1. Crimp-on modular plugs on stranded patch cord
  2. Punch-down of solid copper conductors into insulation displacement contacts Correct answer.
  3. Fiber fusion splicing within a splice tray
  4. Screw terminals under a pressure plate

Explanation

66 blocks use insulation displacement contacts that are punched down with a proper tool, displacing the insulation to make contact with solid copper wire. They are common for cross-connect terminations in voice distribution.

Question 46Low Voltage Systems and Applications

Which standard governs the performance and installation of structured cabling in commercial buildings?

  1. IEEE 802.3
  2. NEC Article 250
  3. TIA-568 Correct answer.
  4. NFPA 72

Explanation

TIA-568 sets the requirements for commercial building telecommunications cabling, including cable performance categories and installation practices. NFPA 72 covers fire alarm systems, Article 250 covers grounding and bonding, and IEEE 802.3 defines Ethernet at the physical and data link layers.

Question 47Low Voltage Systems and Applications

A low voltage installer is running cable through a fire-rated wall. What is the minimum requirement for the penetration?

  1. It must be sealed with a listed firestop system appropriate to the assembly Correct answer.
  2. It may be sealed with duct tape if the hole is small
  3. It may be left open if the cable is plenum rated
  4. It may be filled with expanding foam from a hardware store

Explanation

Penetrations of fire-rated assemblies must be protected with a firestop system listed for that specific construction and penetrating item. The listing ties the sealant and method to the assembly's tested fire resistance.

Question 48Low Voltage Systems and Applications

Which tool is used to verify the pin-to-pin wiring of a newly terminated twisted pair link before it is placed in service?

  1. Cable certifier performing a wire map test Correct answer.
  2. Optical time domain reflectometer
  3. Clamp-on ammeter
  4. Megohmmeter set to 1000 volts

Explanation

A wire map test checks continuity and correct pin assignments at each end, detecting opens, shorts, and crossed or split pairs. Certifiers perform wire map as part of their link testing.

Question 49Low Voltage Systems and Applications

A technician must install a 24-volt control circuit between a thermostat and an air handling unit. Which NEC article most directly governs the installation of this Class 2 circuit?

  1. Article 430
  2. Article 210
  3. Article 680
  4. Article 725 Correct answer.

Explanation

Article 725 covers Class 1, Class 2, and Class 3 remote-control, signaling, and power-limited circuits, which includes thermostat control wiring. Article 210 covers branch circuits, 430 covers motors, and 680 covers pools.

Question 50Low Voltage Systems and Applications

A contractor is installing Category 6A cable in a pathway shared with fluorescent lighting ballasts. Which practice best preserves performance?

  1. Run the data cable through the same connector box as the ballast wiring
  2. Bundle the data cable tightly with the luminaire feed to save space
  3. Route the data cable at least 12 inches from the ballasts and use shielded or properly balanced cable Correct answer.
  4. Use unshielded cable and rely on the twist to reject all interference

Explanation

Fluorescent ballasts are a significant noise source, and maintaining separation from them limits coupled interference. Where separation cannot be maintained, shielded or well-balanced cable helps preserve signal quality.