Locksmith Security Systems 2 — Questions and Answers
Question 1: What does a passive infrared (PIR) motion detector primarily sense?
- Ultrasonic waves reflected off moving objects
- Changes in infrared radiation emitted by warm bodies (Correct answer)
- Microwave frequency shifts caused by movement
- Vibrations transmitted through floors and walls
Correct answer: Changes in infrared radiation emitted by warm bodies
PIR detectors sense changes in infrared energy radiated by warm-bodied intruders moving through the detection zone.
Question 2: A dual-technology motion detector combines PIR with which second technology to reduce false alarms?
- Ultrasonic
- Microwave (Correct answer)
- Laser
- Magnetic
Correct answer: Microwave
Dual-tech detectors pair PIR with microwave sensing and only trigger when both technologies detect motion simultaneously.
Question 3: Which door contact type is considered tamper-resistant because it requires the magnet to be removed before the alarm triggers?
- Surface-mount contact
- Recessed contact (Correct answer)
- Overhead door contact
- Roller-ball contact
Correct answer: Recessed contact
Recessed contacts are embedded in the door and frame, making them harder to defeat with an external magnet.
Question 4: What is the purpose of an End-of-Line (EOL) resistor in an alarm circuit?
- To boost signal strength over long wire runs
- To allow the panel to supervise the circuit for cuts and shorts (Correct answer)
- To reduce current draw from the control panel
- To prevent false alarms caused by lightning
Correct answer: To allow the panel to supervise the circuit for cuts and shorts
An EOL resistor lets the panel continuously monitor the zone circuit, detecting open (cut) or short conditions as separate alarm states.
Question 5: What type of alarm contact is wired so that removing the magnet closes the circuit and triggers the alarm?
- Normally open (NO) (Correct answer)
- Normally closed (NC)
- Double-pole double-throw (DPDT)
- Form-C
Correct answer: Normally open (NO)
A normally open contact completes (closes) the circuit when the door opens, signaling the alarm panel.
Question 6: A glass break detector calibrated for a specific frequency is most effective against which threat scenario?
- Slow cutting of glass with a carbide tool
- Smashing a window to gain rapid entry (Correct answer)
- Drilling through a glass pane
- Removing a window frame intact
Correct answer: Smashing a window to gain rapid entry
Glass break detectors listen for the high-frequency acoustic signature of shattering glass, triggering on sudden impact.
Question 7: When installing a keypad for a residential alarm system, what is the recommended mounting height from the floor?
- 36 inches
- 42 inches
- 48 inches (Correct answer)
- 60 inches
Correct answer: 48 inches
Keypads are typically mounted at 48 inches (4 feet) from the floor for ergonomic reach by most adults.
Locksmith Security Systems 2
What does a passive infrared (PIR) motion detector primarily sense?