Question

an alarm system in which radio signals are used to detect motion; the alarm is tripped when an intruder breaks the radio wave by moving into an rf field. microwave detectors radio frequency fields perimeter control question 29 (1 point) alarm system that typically relies on some sort of transmission such as microwaves, radio waves, or photoelectric light beams. radio frequency fields seismic detector remote alarm question 30 (1 point) controlling access to neighborhoods and buildings and conducting surveillance on specific areas to reduce opportunities for crime to occur. seismic detector remote alarm target hardening

Explanation:

• For the first question, microwave detectors use radio - frequency (RF) signals to detect motion by an intruder breaking the radio wave in an RF field.
• For the second question, alarm systems that use transmission like microwaves, radio waves, or photoelectric light beams are related to radio - frequency fields conceptually as they all involve signal transmission for detection.
• For the third question, controlling access and surveillance to reduce crime opportunities is a form of target hardening which makes a target less vulnerable to crime.

Answer:

• Question 28: A. Microwave detectors
• Question 29: A. Radio Frequency Fields
• Question 30: C. Target Hardening