Ham Radio Technician Class Flashcards

Which is a commonly accepted value for the lowest voltage that can cause a dangerous electric shock?

How does current flowing through the body cause a health hazard?

What is connected to the green wire in a three-wire electrical AC plug?

What is the purpose of a fuse in an electrical circuit?

Why is it unwise to install a 20-ampere fuse in the place of a 5-ampere fuse?

What is a good way to guard against electrical shock at your station?

Which of these precautions should be taken when installing devices for lightning protection in a coaxial cable feedline?

What is one way to recharge a 12-volt lead-acid station battery if the commercial power is out?

What kind of hazard is presented by a conventional 12-volt storage battery?

What can happen if a lead-acid storage battery is charged or discharged too quickly?

Which of the following is good practice when installing ground wires on a tower for lightning protection?

What kind of hazard might exist in a power supply when it is turned off and disconnected?

What safety equipment should always be included in home-built equipment that is powered from 120V AC power circuits?

When should members of a tower work team wear a hard hat and safety glasses?

The lowest voltage that can cause a dangerous electric shock is commonly accepted to be 30 volts.
Current flowing through the body poses health hazards by disrupting cell functions, causing muscle contractions, and heating tissue.
In a three-wire electrical AC plug, the green wire is connected to the safety ground.

A fuse in electrical circuits interrupts power in case of overload.
Installing a 20-ampere fuse in place of a 5-ampere fuse can cause excessive current, potentially leading to fire hazards.
Protective measures against electrical shock include using three-wire cords, connecting to a common safety ground, and utilizing ground-fault interrupters.

Devices for lightning protection in coaxial cables must be grounded to a common plate that connects to an external ground.
A 12-volt lead-acid battery can be recharged by connecting it to a car battery during power outages.
Conventional 12-volt storage batteries can present explosion risks if not properly vented.

Charging or discharging a lead-acid battery too quickly can cause overheating and potentially lead to explosions.
Good practices for grounding wires on towers include using clean right-angle bends and keeping connections short and direct.
Even when disconnected, power supplies can pose shock hazards due to stored charges in large capacitors.

Home-built equipment powered by 120V AC should include a fuse or circuit breaker in series with the AC "hot" conductor.
Hard hats and safety glasses should be worn at all times when working on towers, ensuring safety during any work activities.
Before climbing an antenna tower, it's crucial to put on a climbing harness and safety gear as part of safety precautions.