What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?
The correct answer is C: 47.3 kHz. What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150 is 47.3 kHz. Bandwidth = f/Q = 7.1×10^6 / 150 ≈ 47,333 Hz = 47.3 kHz. For amateur radio operators, this is important for circuit calculations. Understanding this helps when calculating bandwidth.
Exam Tip
Half-power bandwidth = resonant frequency / Q. Think 'B'andwidth = 'F'/'Q'. Bandwidth = 7.1×10^6 / 150 ≈ 47,333 Hz = 47.3 kHz. Not 157.8 Hz, not 315.6 Hz, not 23.67 kHz - just 47.3 kHz.
Memory Aid
"Half-power bandwidth = resonant frequency / Q. Think 'B'andwidth = 'F'/'Q'. Bandwidth = 7.1 MHz / 150 ≈ 47.3 kHz. Important for circuit calculations."
Real-World Application
A resonant circuit with resonant frequency 7.1 MHz and Q of 150: The half-power bandwidth is f/Q = 7.1×10^6 / 150 ≈ 47,333 Hz = 47.3 kHz. This is the bandwidth - 47.3 kHz.
Key Concepts
Why Other Options Are Wrong
Option A (157.8 Hz): Incorrect. 157.8 Hz is too low - bandwidth = 7.1 MHz / 150 ≈ 47.3 kHz. 157.8 Hz is wrong.
Option B (315.6 Hz): Incorrect. 315.6 Hz is too low - bandwidth = 7.1 MHz / 150 ≈ 47.3 kHz. 315.6 Hz is wrong.
Option D (23.67 kHz): Incorrect. 23.67 kHz is too low - bandwidth = 7.1 MHz / 150 ≈ 47.3 kHz. 23.67 kHz is wrong.
题目解析
The correct answer is C: 47.3 kHz. What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150 is 47.3 kHz. Bandwidth = f/Q = 7.1×10^6 / 150 ≈ 47,333 Hz = 47.3 kHz. For amateur radio operators, this is important for circuit calculations. Understanding this helps when calculating bandwidth.
考试技巧
Half-power bandwidth = resonant frequency / Q. Think 'B'andwidth = 'F'/'Q'. Bandwidth = 7.1×10^6 / 150 ≈ 47,333 Hz = 47.3 kHz. Not 157.8 Hz, not 315.6 Hz, not 23.67 kHz - just 47.3 kHz.
记忆口诀
Half-power bandwidth = resonant frequency / Q. Think 'B'andwidth = 'F'/'Q'. Bandwidth = 7.1 MHz / 150 ≈ 47.3 kHz. Important for circuit calculations.
实际应用示例
A resonant circuit with resonant frequency 7.1 MHz and Q of 150: The half-power bandwidth is f/Q = 7.1×10^6 / 150 ≈ 47,333 Hz = 47.3 kHz. This is the bandwidth - 47.3 kHz.
错误选项分析
Option A (157.8 Hz): Incorrect. 157.8 Hz is too low - bandwidth = 7.1 MHz / 150 ≈ 47.3 kHz. 157.8 Hz is wrong. Option B (315.6 Hz): Incorrect. 315.6 Hz is too low - bandwidth = 7.1 MHz / 150 ≈ 47.3 kHz. 315.6 Hz is wrong. Option D (23.67 kHz): Incorrect. 23.67 kHz is too low - bandwidth = 7.1 MHz / 150 ≈ 47.3 kHz. 23.67 kHz is wrong.
知识点
Half-power bandwidth, Resonant circuit, Resonant frequency 7.1 MHz, Q 150, 47.3 kHz
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.