CAT Knowledge and Skills 2 — Questions and Answers
Question 1: Which wire gauge is most commonly used for connecting alarm system sensors to a control panel over short distances?
- 22 AWG (Correct answer)
- 14 AWG
- 10 AWG
- 6 AWG
Correct answer: 22 AWG
22 AWG is the standard wire gauge for low-voltage alarm sensor runs due to its balance of flexibility and conductivity.
Question 2: What is the purpose of an End-of-Line (EOL) resistor in a supervised alarm circuit?
- To indicate a tamper or cut wire condition to the panel (Correct answer)
- To limit current through the siren
- To prevent voltage spikes from lightning
- To balance speaker impedance
Correct answer: To indicate a tamper or cut wire condition to the panel
An EOL resistor allows the panel to detect opens (cut wires) or shorts by monitoring the circuit's resistance value.
Question 3: A passive infrared (PIR) motion detector primarily detects changes in what physical property?
- Infrared radiation emitted by moving warm bodies (Correct answer)
- Ultrasonic reflections from moving objects
- Visible light interruptions across a beam
- Microwave Doppler frequency shifts
Correct answer: Infrared radiation emitted by moving warm bodies
PIR sensors detect changes in infrared energy caused by a warm body moving through the sensor's field of view.
Question 4: What NEC article primarily governs the installation of fire alarm systems?
- Article 760 (Correct answer)
- Article 800
- Article 725
- Article 310
Correct answer: Article 760
NEC Article 760 covers fire alarm systems, including wiring methods and conductor requirements.
Question 5: When testing a heat detector's fixed-temperature rating, which tool is the safest and most recommended method?
- A listed heat detector test instrument (heat gun) (Correct answer)
- An open flame lighter held beneath the detector
- A standard hair dryer at maximum heat
- Boiling water poured over the detector
Correct answer: A listed heat detector test instrument (heat gun)
Listed heat detector test instruments apply controlled, calibrated heat without risking damage or false alarm misinterpretation.
Question 6: Which battery type is most commonly used as the standby power source in residential alarm control panels?
- Sealed lead-acid (SLA) (Correct answer)
- Lithium primary
- Alkaline AA cells
- Nickel-cadmium (NiCd)
Correct answer: Sealed lead-acid (SLA)
Sealed lead-acid batteries are standard for alarm panel backup due to their reliable discharge characteristics and rechargeable nature.
Question 7: A technician notices a 'low battery' trouble signal on a wireless smoke detector. What is the correct action?
- Replace the battery with the manufacturer-specified type and test the device (Correct answer)
- Ignore it until the detector triggers an alarm
- Reset the panel remotely and monitor for 24 hours
- Replace the entire detector immediately
Correct answer: Replace the battery with the manufacturer-specified type and test the device
The correct response is to replace the battery with the specified type and then functionally test the detector to confirm proper operation.
CAT Knowledge and Skills 2
Which wire gauge is most commonly used for connecting alarm system sensors to a control panel over short distances?