Nevada (NV) C-2D Low Voltage Practice Exam Questions With Correct Answers Verified | Instant Download Pdf

1. A low voltage installer in Nevada holding a C-2D license is primarily permitted to work on systems that do not exceed: A) 50 volts AC and 75 volts DC B) 30 volts AC and 60 volts DC C) 100 volts AC and 100 volts DC D) 24 volts AC and 48 volts DC Answer: A Explanation: The Nevada C-2D classification covers installation, alteration, and repair of low voltage systems where the voltage does not exceed 50 volts AC (RMS) or 75 volts DC. This includes most communication, security, fire alarm, and control circuits, but excludes power wiring above these limits. 2. According to NEC® Article 725, Class 2 circuits are considered safe from fire and electric shock primarily because: A) They are always grounded B) Their power output is limited by a listed Class 2 power supply C) They use only solid copper conductors D) They must be installed in metal conduitAnswer: B Explanation: Class 2 circuits have power limitations (e.g., ≤100 VA for voltages ≤30V) imposed by listed power sources (transformers, power supplies). These limits reduce fire and shock risks, allowing simpler wiring methods such as cable trays or plenum spaces without conduit. 3. When installing a residential fire alarm system under the C-2D scope, powerlimited fire alarm cables must be separated from Class 1 circuits by at least: A) 1 inch B) 2 inches C) 6 inches D) 12 inches Answer: B Explanation: NEC® 760.136 requires power-limited fire alarm cables (FPL, FPLP) to maintain a minimum 2-inch separation from Class 1, power, or lighting conductors unless separated by a barrier or raceway. This prevents dangerous voltage induction. 4. A C-2D contractor installs a door access control system using 24 VDC. The cable must be supported within __________ inches of a junction box or fitting. A) 6 B) 8 C) 12 D) 18 Answer: C Explanation: NEC® 800.110(A) requires cable support within 12 inches of abox or fitting for communication circuits; this is analogous for access control under Article 725. It ensures strain relief and prevents damage at terminations. 5. Which of the following is NOT permitted for a Nevada C-2D licensee to install? A) Cat 6 network cabling in a commercial building B) 120 VAC to a doorbell transformer C) Fiber optic backbone cable D) 24 VAC thermostat wiring for an HVAC system Answer: B Explanation: The C-2D license covers low voltage circuits only. The primary side (120 VAC) of a doorbell transformer is line voltage, requiring a C-2 (electrical) or higher license. The low voltage secondary side is allowed under C-2D. 6. The minimum bending radius for a typical 4-pair UTP Cat 6 cable during installation is: A) 2 times the cable diameter B) 4 times the cable diameter C) 6 times the cable diameter D) 10 times the cable diameter Answer: B Explanation: ANSI/TIA-568 standards specify a minimum bending radius of four times the cable diameter for unshielded twisted pair. Excessive bending damages impedance and causes crosstalk or return loss failures.7. Fire alarm circuits installed in a building’s environmental air handling plenum must use cable marked: A) CMX B) CMR C) CMP D) CMG Answer: C Explanation: CMP (Communications Plenum) cable has low smoke and flame spread characteristics per NFPA 262. NEC® 760.179 requires plenum-rated fire alarm cable (FPLP) or CMP for these spaces to limit toxic fume propagation. 8. The maximum allowable pull tension for a 24-AWG solid UTP cable is approximately: A) 5 lbf (22 N) B) 12 lbf (53 N) C) 25 lbf (111 N) D) 50 lbf (222 N) Answer: C Explanation: For 24 AWG solid copper, maximum recommended pull tension is about 25 lbf. Higher tension stretches conductors, altering impedance and causing bit errors. Use a pulling lubricant and tension gauge. 9. According to Nevada Administrative Code (NAC) 624, a C-2D contractor must display their license number on:A) All advertising, contracts, and vehicles B) Only business cards C) Only job site signs for projects over $10,000 D) The inside of the contractor’s office Answer: A Explanation: NAC 624.690 requires license number display on all advertising materials, business documents (proposals, contracts, invoices), and vehicles used for business to ensure consumer transparency and traceability. 10. When installing a network cable through a fire-rated wall, the correct fire-stopping method is: A) A plastic bushing B) Duct seal compound C) An intumescent putty or firestop caulking listed for the cable type D) Expanding foam insulation Answer: C Explanation: Fire-rated penetrations require listed firestop systems. Intumescent putty expands when heated to seal gaps around cables, maintaining the wall’s rating. Duct seal or standard foam is not fire-rated. 11. A C-2D technician finds existing low voltage cables tied to sprinkler pipes. This is: A) Acceptable if the cables are secured with plastic ties B) Acceptable only for temporary installationsC) Prohibited because support from other trade’s pipes is not allowed D) Allowed only in residential buildings Answer: C Explanation: NEC® 800.113 prohibits supporting communication cables from any pipe or conduit used for plumbing, heating, or fire protection. Doing so risks physical damage and violates the cable support integrity requirement. 12. The maximum distance for a Category 6 Ethernet channel (including patch cords) is: A) 55 meters B) 90 meters C) 100 meters D) 150 meters Answer: C Explanation: TIA/EIA 568-C.2 specifies 100 meters total channel length (90 m permanent link plus 10 m patch cords). Exceeding this increases attenuation and crosstalk beyond IEEE 802.3ab Gigabit Ethernet limits. 13. Under NEC® 725.144, Class 2 cables installed in a vertical riser between floors must be: A) Riser-rated (CMR) or higher B) Any CM rating if bundled C) Installed only in metal conduit D) Plenum-rated regardless of locationAnswer: A Explanation: Riser applications require CMR (Riser) or CMP (Plenum) cable because of stricter flame spread limitations preventing fire from spreading between floors. CM (general purpose) cannot be used in vertical shafts. 14. The primary purpose of a fire alarm control panel’s “ground fault” LED is to indicate: A) That a wire is touching earth ground B) That AC power is reversed C) A low battery condition D) An open circuit on a zone Answer: A Explanation: Ground faults occur when a conductor unintentionally contacts building ground, potentially causing false alarms or preventing proper supervision. Fire panels monitor for this to maintain integrity per NFPA 72.