What is the output waveform of an unfiltered full-wave rectifier connected to a resistive load?
The correct answer is A: A series of DC pulses at twice the frequency of the AC input. The output waveform of an unfiltered full-wave rectifier connected to a resistive load is a series of DC pulses at twice the frequency of the AC input. Full-wave rectification produces pulses at 120 Hz (for 60 Hz input) or 100 Hz (for 50 Hz input). For amateur radio operators, this explains unfiltered rectifier output. Understanding this helps when analyzing power supplies.
Exam Tip
Unfiltered full-wave output = DC pulses at twice AC frequency. Think 'F'ull-'W'ave = 'F'ull cycle rectified = 'T'wice frequency pulses. Full-wave produces DC pulses at twice the AC input frequency. Not same frequency, not sine wave, not steady DC - just pulses at 2× frequency.
Memory Aid
"Unfiltered full-wave output = DC pulses at twice AC frequency. Think 'F'ull-'W'ave = 'T'wice frequency pulses. Full-wave produces DC pulses at twice the AC input frequency. Filtering needed for steady DC."
Real-World Application
An unfiltered full-wave rectifier with 60 Hz AC input produces DC pulses at 120 Hz (twice the frequency). The output is a series of positive DC pulses, not steady DC. Filtering (capacitors/inductors) is needed to smooth this into steady DC. This is why filters are essential in power supplies.
Key Concepts
Why Other Options Are Wrong
Option B: Incorrect. Pulses aren't at the same frequency as AC input - full-wave produces pulses at twice the input frequency. Same frequency would be half-wave.
Option C: Incorrect. Output isn't a sine wave at half frequency - it's DC pulses, not a sine wave, and at twice frequency, not half. Sine wave and half frequency are both wrong.
Option D: Incorrect. Output isn't steady DC voltage - unfiltered output has pulses/ripple, not steady DC. Steady DC requires filtering.
题目解析
The correct answer is A: A series of DC pulses at twice the frequency of the AC input. The output waveform of an unfiltered full-wave rectifier connected to a resistive load is a series of DC pulses at twice the frequency of the AC input. Full-wave rectification produces pulses at 120 Hz (for 60 Hz input) or 100 Hz (for 50 Hz input). For amateur radio operators, this explains unfiltered rectifier output. Understanding this helps when analyzing power supplies.
考试技巧
Unfiltered full-wave output = DC pulses at twice AC frequency. Think 'F'ull-'W'ave = 'F'ull cycle rectified = 'T'wice frequency pulses. Full-wave produces DC pulses at twice the AC input frequency. Not same frequency, not sine wave, not steady DC - just pulses at 2× frequency.
记忆口诀
Unfiltered full-wave output = DC pulses at twice AC frequency. Think 'F'ull-'W'ave = 'T'wice frequency pulses. Full-wave produces DC pulses at twice the AC input frequency. Filtering needed for steady DC.
实际应用示例
An unfiltered full-wave rectifier with 60 Hz AC input produces DC pulses at 120 Hz (twice the frequency). The output is a series of positive DC pulses, not steady DC. Filtering (capacitors/inductors) is needed to smooth this into steady DC. This is why filters are essential in power supplies.
错误选项分析
Option B: Incorrect. Pulses aren't at the same frequency as AC input - full-wave produces pulses at twice the input frequency. Same frequency would be half-wave. Option C: Incorrect. Output isn't a sine wave at half frequency - it's DC pulses, not a sine wave, and at twice frequency, not half. Sine wave and half frequency are both wrong. Option D: Incorrect. Output isn't steady DC voltage - unfiltered output has pulses/ripple, not steady DC. Steady DC requires filtering.
知识点
Full-wave rectifier, Unfiltered output, DC pulses, Twice the frequency
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.