What health hazard is presented by electrical current flowing through the body?
The correct answer is D: All these choices are correct. Electrical current flowing through the body can cause injury by heating tissue, disrupting electrical functions of cells, and causing involuntary muscle contractions. All three are serious hazards. Current heats tissue (causing burns), interferes with nerve and muscle function (potentially stopping the heart), and causes muscles to contract (preventing you from letting go). For amateur radio operators, understanding these hazards emphasizes the importance of electrical safety. Even relatively low currents can be dangerous or fatal.
Exam Tip
All three are hazards: tissue heating, cell disruption, muscle contractions. When all listed effects are valid hazards of electrical current, 'all of the above' is usually the answer. All can cause serious injury or death.
Memory Aid
"All three are hazards: Tissue heating, Cell disruption, Muscle contractions. Think 'A'll 'C'urrent 'H'azards. Electrical current through the body can cause burns, disrupt heart rhythm, and cause muscle contractions - all dangerous."
Real-World Application
You accidentally touch a live 120V AC wire. Current flows through your body, (1) heating tissue and causing burns at entry/exit points, (2) disrupting your heart's electrical rhythm (potentially causing cardiac arrest), and (3) causing your muscles to contract, making it difficult or impossible to let go. All three effects are dangerous and can be fatal.
Key Concepts
Why Other Options Are Wrong
Option A: While correct, this is incomplete. Current also disrupts cell functions and causes muscle contractions.
Option B: While correct, this is incomplete. Current also heats tissue and causes muscle contractions.
Option C: While correct, this is incomplete. Current also heats tissue and disrupts cell functions.
题目解析
The correct answer is D: All these choices are correct. Electrical current flowing through the body can cause injury by heating tissue, disrupting electrical functions of cells, and causing involuntary muscle contractions. All three are serious hazards. Current heats tissue (causing burns), interferes with nerve and muscle function (potentially stopping the heart), and causes muscles to contract (preventing you from letting go). For amateur radio operators, understanding these hazards emphasizes the importance of electrical safety. Even relatively low currents can be dangerous or fatal.
考试技巧
All three are hazards: tissue heating, cell disruption, muscle contractions. When all listed effects are valid hazards of electrical current, 'all of the above' is usually the answer. All can cause serious injury or death.
记忆口诀
All three are hazards: Tissue heating, Cell disruption, Muscle contractions. Think 'A'll 'C'urrent 'H'azards. Electrical current through the body can cause burns, disrupt heart rhythm, and cause muscle contractions - all dangerous.
实际应用示例
You accidentally touch a live 120V AC wire. Current flows through your body, (1) heating tissue and causing burns at entry/exit points, (2) disrupting your heart's electrical rhythm (potentially causing cardiac arrest), and (3) causing your muscles to contract, making it difficult or impossible to let go. All three effects are dangerous and can be fatal.
错误选项分析
Option A: While correct, this is incomplete. Current also disrupts cell functions and causes muscle contractions. Option B: While correct, this is incomplete. Current also heats tissue and causes muscle contractions. Option C: While correct, this is incomplete. Current also heats tissue and disrupts cell functions.
知识点
Electrical shock, Body current, Electrical hazards, Safety
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.