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207 what are the various types of motion detectors a

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207 What are the various types of motion detectors? A. Wave patterns and radar B. Audio, wave patterns, and capacitance C. Infrared and capacitance
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D. Audio and capacitance Answer: B See Chapter 11. Audio detectors are sensitive, passive microphones. Wave-pattern motion detectors emit wave patterns and note any changes in return signals, indicating moving objects. Capacitance can detect motion only a few inches in front of the detector. 208 Which of the following is NOT a characteristic of passive electronic access cards? A. They contain batteries that must be changed or charged. B. They're powered by the RF field transmitted by the reader. C. They transmit at a frequency different from the frequency emitted by the reader. D. They don't need to touch the reader, instead working by proximity. Answer: A See Chapter 11. Passive electronic cards have no batteries because they’re powered by the radio frequency (RF) field emitted by the reader. 209 Which of the following is NOT a characteristic of active electronic access cards? A. They contain batteries that must be changed or charged. B. They’re powered by the RF field transmitted by the reader. C. They transmit at a frequency different from the frequency emitted by the reader. D. They don't need to touch the reader, instead working by proximity. Answer: B See Chapter 11. Active electronic access cards have a power supply and aren’t powered by the reader’s radio frequency (RF) transmitter. 210 Which of the following is NOT an advantage of cipher locks over access-card locks? A. Cipher locks are independent and work even when centralized systems can’t. B. A cipher lock may be more cost-effective than an access-card lock for one door. C. Cipher locks offer better centralized control than do access-card locks.
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D. Cipher locks are self-contained, requiring no external power or wiring. Answer: C See Chapter 11. Cipher locks usually offer no centralized control at all. 211 Memory that's used to store computer instructions and data is known as: A. UART B. SIMM C. Cache D. ROM Answer: C See Chapter 12. Cache memory holds instructions and data that are likely to be frequently accessed. Cache memory is faster than RAM, so it can contribute to faster performance. 212 Firmware is generally stored on A. ROM or EPROM B. Tape C. RAM D. Any removable media Answer: A See Chapter 12. Firmware is software that's seldom changed. Firmware is generally used to control lower-level functions in computer hardware and embedded systems. 213 What's the purpose of memory protection? A. It protects memory from malicious code. B. It prevents a program from being able to access memory used by another program. C. Memory protection is another term used to describe virtual memory backing store. D. It assures that hardware refresh is frequent enough to maintain memory integrity.
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