Deep Dive: E7C01
The correct answer is D: A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between the input and output. How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output is that a capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between the input and output. Pi-network low-pass has capacitors to ground and inductor in series. For amateur radio operators, this is important for filter design. Understanding this helps when designing filters.
Why Other Answers Are Wrong
Option A: Incorrect. Two inductors in series with capacitor to ground isn't Pi-network low-pass - Pi-network has capacitors to ground and inductor in series. Two inductors isn't correct. Option B: Incorrect. Two capacitors in series with inductor to ground isn't Pi-network low-pass - Pi-network has capacitors to ground and inductor in series. Two capacitors in series isn't correct. Option C: Incorrect. Two inductors to ground with capacitor between input/output isn't Pi-network low-pass - Pi-network has capacitors to ground and inductor in series. Two inductors to ground isn't correct.
Exam Tip
Low-pass Pi-network arrangement = capacitor input to ground, capacitor output to ground, inductor between input/output. Think 'P'i-network 'L'ow-'P'ass = 'C'apacitors to 'G'round, 'I'nductor in 'S'eries. Pi-network low-pass has capacitors to ground and inductor in series. Not two inductors, not two capacitors in series, not two inductors to ground - just capacitors to ground, inductor in series.
Memory Aid
Low-pass Pi-network arrangement = capacitor input to ground, capacitor output to ground, inductor between input/output. Think 'P'i-network = 'C'apacitors to 'G'round, 'I'nductor 'S'eries. Pi-network low-pass has capacitors to ground and inductor in series. Important for filter design.
Real-World Example
A low-pass filter Pi-network: A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between the input and output. This forms the Pi (π) shape. This is the arrangement - capacitors to ground, inductor in series.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E7C
Reference: 2024-2028 Question Pool · E7 - Practical Circuits
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E7C topic.