Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?
The correct answer is C: Large bodies of water. Atmospheric ducts capable of propagating microwave signals often form over what geographic feature is large bodies of water. Water bodies create temperature inversions that form ducts. For amateur radio operators, this is important for microwave propagation. Understanding this helps when operating on microwave bands.
Exam Tip
Atmospheric ducts form over = large bodies of water. Think 'A'tmospheric 'D'ucts = 'A'cross 'D'amp water. Water bodies create temperature inversions that form ducts. Not mountain ranges, not stratocumulus, not nimbus - just large bodies of water.
Memory Aid
"Atmospheric ducts form over = large bodies of water. Think 'A'tmospheric 'D'ucts = 'W'ater. Water bodies create temperature inversions that form ducts. Important for microwave propagation."
Real-World Application
Atmospheric ducts for microwave signals: They often form over large bodies of water (oceans, large lakes). The water creates temperature inversions in the atmosphere, which can trap and guide microwave signals beyond the normal horizon. This is the geographic feature - large bodies of water.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Mountain ranges don't typically form ducts - large bodies of water do. Mountain ranges isn't the feature.
Option B: Incorrect. Stratocumulus clouds don't form ducts - large bodies of water do. Stratocumulus clouds isn't the feature.
Option D: Incorrect. Nimbus clouds don't form ducts - large bodies of water do. Nimbus clouds isn't the feature.
题目解析
The correct answer is C: Large bodies of water. Atmospheric ducts capable of propagating microwave signals often form over what geographic feature is large bodies of water. Water bodies create temperature inversions that form ducts. For amateur radio operators, this is important for microwave propagation. Understanding this helps when operating on microwave bands.
考试技巧
Atmospheric ducts form over = large bodies of water. Think 'A'tmospheric 'D'ucts = 'A'cross 'D'amp water. Water bodies create temperature inversions that form ducts. Not mountain ranges, not stratocumulus, not nimbus - just large bodies of water.
记忆口诀
Atmospheric ducts form over = large bodies of water. Think 'A'tmospheric 'D'ucts = 'W'ater. Water bodies create temperature inversions that form ducts. Important for microwave propagation.
实际应用示例
Atmospheric ducts for microwave signals: They often form over large bodies of water (oceans, large lakes). The water creates temperature inversions in the atmosphere, which can trap and guide microwave signals beyond the normal horizon. This is the geographic feature - large bodies of water.
错误选项分析
Option A: Incorrect. Mountain ranges don't typically form ducts - large bodies of water do. Mountain ranges isn't the feature. Option B: Incorrect. Stratocumulus clouds don't form ducts - large bodies of water do. Stratocumulus clouds isn't the feature. Option D: Incorrect. Nimbus clouds don't form ducts - large bodies of water do. Nimbus clouds isn't the feature.
知识点
Atmospheric ducts, Microwave signals, Large bodies of water, Duct propagation
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.