Ham Radio Technician Class Flashcards

Questions and Answers

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

120 volts

300 volts

12 volts

30 volts (correct)

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

By heating tissue

It disrupts the electrical functions of cells

All of these choices are correct (correct)

It causes involuntary muscle contractions

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

Neutral

Safety ground (correct)

The white wire

Hot

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

To interrupt power in case of overload Signup and view all the answers

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

Excessive current could cause a fire Signup and view all the answers

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

All of these choices are correct Signup and view all the answers

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

Ground all of the protectors to a common plate Signup and view all the answers

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

Connect the battery to a car's battery and run the engine Signup and view all the answers

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

Explosive gas can collect if not properly vented Signup and view all the answers

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

The battery could overheat and give off flammable gas or explode Signup and view all the answers

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

Ensure that connections are short and direct Signup and view all the answers

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

You might receive an electric shock from stored charge in large capacitors Signup and view all the answers

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

A fuse or circuit breaker in series with the AC 'hot' conductor Signup and view all the answers

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

At all times when any work is being done on the tower Signup and view all the answers

Study Notes

Electrical Safety Basics

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.

Fuses and Circuit Protection

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.

Lightning Protection and Charging Batteries

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.

Battery Care and Grounding Practices

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.

Safety Equipment and Precautions

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.

Description

This quiz features flashcards designed for the Ham Radio Technician Class, covering essential concepts and safety measures in amateur radio. Test your knowledge about voltage levels and health hazards related to electrical shocks through engaging question-and-answer format.