G0B: Safety in the ham shack: electrical shock and treatment, grounding, fusing, interlocks, wiring, antenna and tower safety
G0B01:
Which wire(s) in a four-conductor line cord should be attached to fuses or circuit breakers in a device operated from a 240-VAC single-phase source?
Only the "hot" (black and red) wires
Only the "neutral" (white) wire
Only the ground (bare) wire
All wires
G0B02:
What is the minimum wire size that may be safely used for a circuit that draws up to 20 amperes of continuous current?
AWG number 12
AWG number 20
AWG number 16
AWG number 8
G0B03:
Which size of fuse or circuit breaker would be appropriate to use with a circuit that uses AWG number 14 wiring?
15 amperes
100 amperes
60 amperes
30 amperes
G0B04:
What is the mechanism by which electrical shock can be lethal?
Current through the heart can cause the heart to stop pumping
A large voltage field can induce currents in the brain
Heating effects in major organs can cause organ failure
All of these choices are correct
G0B05:
Which of the following conditions will cause a Ground Fault Circuit Interrupter (GFCI) to disconnect the 120 or 240 Volt AC line power to a device?
Current flowing from the hot wire to ground
Current flowing from the hot wire to the neutral wire
Over-voltage on the hot wire
All of these choices are correct
G0B06:
Why must the metal chassis of every item of station equipment be grounded (assuming the item has such a chassis)?
It ensures that hazardous voltages cannot appear on the chassis
It prevents blowing of fuses in case of an internal short circuit
It provides a ground reference for the internal circuitry
It ensures that the neutral wire is grounded
G0B07:
Which of the following should be observed for safety when climbing on a tower using a safety belt or harness?
Always attach the belt safety hook to the belt "D" ring with the hook opening away from the tower
Never lean back and rely on the belt alone to support your weight
Ensure that all heavy tools are securely fastened to the belt D ring
Make sure that your belt is grounded at all times
G0B08:
What should be done by any person preparing to climb a tower that supports electrically powered devices?
Make sure all circuits that supply power to the tower are locked out and tagged
Notify the electric company that a person will be working on the tower
Ground the base of the tower
Disconnect the feed-line for every antenna at the station
G0B09:
Why is it not safe to use soldered joints with the wires that connect the base of a tower to a system of ground rods?
A soldered joint will likely be destroyed by the heat of a lightning strike
The resistance of solder is too high
Solder flux will prevent a low conductivity connection
Solder has too high a dielectric constant to provide adequate lightning protection
G0B10:
Which of the following is a danger from lead-tin solder?
Lead can contaminate food if hands are not washed carefully after handling
High voltages can cause lead-tin solder to disintegrate suddenly
Tin in the solder can "cold flow" causing shorts in the circuit
RF energy can convert the lead into a poisonous gas
G0B11:
Which of the following is good engineering practice for lightning protection grounds?
They must be bonded together with all other grounds
They must be bonded to all buried water and gas lines
Bends in ground wires must be made as close as possible to a right angle
Lightning grounds must be connected to all ungrounded wiring
G0B12:
What is the purpose of a transmitter power supply interlock?
To ensure that dangerous voltages are removed if the cabinet is opened
To prevent unauthorized access to a transmitter
To guarantee that you cannot accidentally transmit out of band
To shut off the transmitter if too much current is drawn
G0B13:
Which of the following is the most hazardous type of electrical energy?
60 cycle Alternating current
Direct Current
Radio Frequency
All of these choices are correct
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