California C-7 Low Voltage Systems License Exam Prep: Free Practice Questions & Explanations (82 chars) /CA C-7 Low Voltage Contractor Exam | Complete Practice Test & Answers (80 chars)

California C-7 Low Voltage Systems License Exam Prep:
Free Practice Questions & Explanations (82 chars) /CA C-7
Low Voltage Contractor Exam | Complete Practice Test &
Answers (80 chars)



Introduction

Preparing for the California C-7 Low Voltage Systems Contractor License Exam? Passing this
exam administered by the Contractors State License Board (CSLB) is a crucial step toward
becoming a licensed low-voltage, security, fiber optic, or AV contractor in California.

This practice bank features realistic exam questions designed to match the scope, technical
depth, and standards required for the C-7 trade test. Every question includes a detailed
explanation citing relevant codes and standards, including the California Electrical Code
(CEC), NFPA 72 (National Fire Alarm and Signal Code), ANSI/TIA Structured Cabling
Standards, and Cal/OSHA Safety Orders.

Key Topics Covered in This Exam Bank:

 ⚡ Electrical & Circuit Fundamentals: Ohm’s Law, power calculations ($P = VI$),
series/parallel resistance, and transformer sizing.
 🔒 Access Control & Intrusion Detection: Fail-safe vs. fail-secure hardware, Wiegand
& OSDP protocols, dual-tech sensors, and door strikes.
 🔥 Fire Alarm Systems & NFPA 72: Standby battery calculations, detector placement,
Class A vs. Class B circuits, and notification appliance spacing.
 🌐 Structured Cabling & Networking: Cat6/6A specifications, T568A/B pinouts, PoE
standard power levels, and fiber optic testing (OTDR/OPM).
 🔊 Audio/Visual & CCTV Systems: 70V distribution systems, 75-ohm video cabling,
camera focal length, and Wide Dynamic Range (WDR).
 📋 California Codes & Safety (Cal/OSHA): Title 8 safety rules, ladder extension
standards, trenching depth, GFCI requirements, and CSLB business law.




Q1

,According to the California Electrical Code (CEC), Article 725, Class 2 low-voltage
cables installed in environmental air-handling spaces (plenums) must carry which
listing mark?

 A) CL2
 B) CL2R
 C) CL2P
 D) CL2X

Correct Answer: C) CL2P

Explanation: Per CEC Article 725, cables installed in ductwork, plenums, and other spaces
used for environmental air must be listed as plenum-rated (CL2P or CMP for
communications) due to low smoke-producing and fire-resistant characteristics.

Q2

What is the maximum distance a Category 6 twisted-pair Ethernet cable can run for a
standard 1000BASE-T channel link, including patch cords?

 A) 50 meters (164 feet)
 B) 90 meters (295 feet)
 C) 100 meters (328 feet)
 D) 150 meters (492 feet)

Correct Answer: C) 100 meters (328 feet)

Explanation: According to ANSI/TIA-568 standards, a complete copper channel is limited
to 100 meters (328 feet) total—typically comprised of 90 meters of solid core permanent
link cable and up to 10 meters combined of stranded patch cords.

,Q3

In a 70-volt commercial audio distribution system, what is the total power load on an
amplifier if four speakers are connected, each tapped at 5 Watts?

 A) 5 Watts
 B) 10 Watts
 C) 20 Watts
 D) 70 Watts

Correct Answer: C) 20 Watts

Explanation: In constant-voltage systems (70V/100V), speaker transformers are wired in
parallel, and total power draw is calculated by adding the individual tap wattages together:

$$\text{Total Power} = 4 \times 5\text{W} = 20\text{ Watts}$$

To prevent amplifier clipping, good design guidelines recommend keeping total tap wattage
below 80% of the amplifier's continuous rated power output.

Q4

According to Cal/OSHA Title 8, when working on an extension ladder, what is the
required ratio of horizontal setback distance to the working length of the ladder?

 A) 1:2
 B) 1:3
 C) 1:4
 D) 1:5

Correct Answer: C) 1:4

, Explanation: Cal/OSHA Title 8 Section 3276 requires non-self-supporting extension
ladders to be positioned at an angle where the horizontal distance from the top support to
the base is 1 foot for every 4 feet of working ladder height (75.5 degrees).

Q5

Under CEC Article 760, what is the maximum continuous current permitted for a
Power-Limited Fire Alarm (PLFA) secondary power supply circuit?

 A) 1.5 Amps
 B) 8.0 Amps
 C) 10.0 Amps
 D) 20.0 Amps

Correct Answer: B) 8.0 Amps

Explanation: CEC 760 limiting criteria specifies that the maximum current capability for
PLFA equipment under secondary fault or overload conditions cannot exceed 8 Amps (or
maximum power rating of 100 VA).

Q6

In an IP surveillance system, IEEE 802.3at (PoE+) provides a maximum power output
at the Type 2 Power Sourcing Equipment (PSE) port of:

 A) 15.4 Watts
 B) 30.0 Watts
 C) 60.0 Watts
 D) 90.0 Watts