What is the cause of short-term radio blackouts?
The correct answer is D: Solar flares. What is the cause of short-term radio blackouts is solar flares. Solar flares cause sudden ionization that absorbs HF signals. For amateur radio operators, this is important for understanding propagation disruptions. Understanding this helps when experiencing blackouts.
Exam Tip
Short-term radio blackout cause = solar flares. Think 'S'hort-'T'erm 'B'lackout = 'S'olar 'F'lares. Solar flares cause sudden ionization that absorbs HF signals. Not CME, not sunspots, not magnetic field - just solar flares.
Memory Aid
"Short-term radio blackout cause = solar flares. Think 'S'hort-'T'erm = 'S'olar 'F'lares. Solar flares cause sudden ionization that absorbs HF signals. Important for understanding propagation disruptions."
Real-World Application
Short-term radio blackouts: They're caused by solar flares. When a solar flare occurs, it creates sudden ionization in the D layer of the ionosphere, which absorbs HF signals and causes immediate blackouts. This is different from coronal mass ejections which cause longer-term effects. This is the cause - solar flares.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Coronal mass ejections cause longer-term effects, not short-term blackouts - solar flares cause short-term blackouts. CME isn't the cause.
Option B: Incorrect. Sunspots on solar equator don't cause short-term blackouts - solar flares do. Sunspots isn't the cause.
Option C: Incorrect. North-oriented interplanetary magnetic field doesn't cause short-term blackouts - solar flares do. Magnetic field orientation isn't the cause.
题目解析
The correct answer is D: Solar flares. What is the cause of short-term radio blackouts is solar flares. Solar flares cause sudden ionization that absorbs HF signals. For amateur radio operators, this is important for understanding propagation disruptions. Understanding this helps when experiencing blackouts.
考试技巧
Short-term radio blackout cause = solar flares. Think 'S'hort-'T'erm 'B'lackout = 'S'olar 'F'lares. Solar flares cause sudden ionization that absorbs HF signals. Not CME, not sunspots, not magnetic field - just solar flares.
记忆口诀
Short-term radio blackout cause = solar flares. Think 'S'hort-'T'erm = 'S'olar 'F'lares. Solar flares cause sudden ionization that absorbs HF signals. Important for understanding propagation disruptions.
实际应用示例
Short-term radio blackouts: They're caused by solar flares. When a solar flare occurs, it creates sudden ionization in the D layer of the ionosphere, which absorbs HF signals and causes immediate blackouts. This is different from coronal mass ejections which cause longer-term effects. This is the cause - solar flares.
错误选项分析
Option A: Incorrect. Coronal mass ejections cause longer-term effects, not short-term blackouts - solar flares cause short-term blackouts. CME isn't the cause. Option B: Incorrect. Sunspots on solar equator don't cause short-term blackouts - solar flares do. Sunspots isn't the cause. Option C: Incorrect. North-oriented interplanetary magnetic field doesn't cause short-term blackouts - solar flares do. Magnetic field orientation isn't the cause.
知识点
Short-term radio blackouts, Solar flares, Propagation disruption, Ionization
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.