Untitled Deck Flashcards
What is the classification for a low voltage electrical system which current flows through continuously, except when the circuit is open to allow a signal to be sent?
Closed
What is the gas pressure inside the tube of a neon lamp when the electrode wire is tested with a high tension spark coil?
A minimum of 50mm under green
Which of the following statements comparing two electric discharge signs is true if one has a smaller tubing diameter?
The load impedance in sign A is greater than that of sign B
Corrosion currents are usually measured in?
Milliamps
A brass service cock in a steel line would tend to become the?
Cathode
What has been accomplished when the source and load impedance are made equal for maximum power transfer?
Impedance matching
The ratio between a sound level that is just audible and other sound levels is indicated in?
Decibels
What device corrects an impedance mismatch and connects cables to other cables or equipment?
Balun
What error may be caused if a technician does not connect a terminator on an unused splitter port at the end of a TV distribution line?
Signal reflections or ghosting
What keeps the alarm circuit activated even if the protective circuit is restored to normal?
Latching relay
What is the strategy called when office telecommunication cables are routed into designated local cable rooms for room connections?
3 point connection
What depth is a 40 foot wood pole set?
6 feet
What is a primary advantage that optical fiber has over copper cable pairs?
EMI immunity
What eliminates electromagnetic interference from entering a hard wired alarm system control panel?
Fiber optic cable
An ohmmeter reading of zero ohms indicates which of the following?
A short circuit
What is a voltmeter used to measure?
Electric pressure
An ohm meter reading of infinity indicates which of the following conditions?
Open circuit
Electrical pressure or electromotive force is measured in?
Volts
What is the ability of a material to permit the flow of electrons through it called?
Conductance
All of the following are incandescent lamp base types except?
Standard
What will happen to the reading on an ammeter set to low if you wrap the wire around twice?
Double the reading
What type of power does an alternator produce?
AC
What is it customary to refer to electromotive force as?
Voltage
How are fuses rated?
Both amperes and voltage
What procedure helps defeat tampering with a shunt lock on older systems?
Wiring the shunt lock directly to the alarm panel
What type of relay continues the annunciator when power is no longer applied?
Drop latch
All of the following are space detectors except?
Bill trap detector
