Deep Dive: G9C02
The correct answer is B: 1/2 wavelength. The approximate length of the driven element of a Yagi antenna is 1/2 wavelength. The driven element is typically about 1/2 wavelength, slightly shorter than resonant due to element interactions. For amateur radio operators, this is fundamental Yagi design. Understanding this helps when building Yagi antennas.
Why Other Answers Are Wrong
Option A (1/4 wavelength): Incorrect. 1/4 wavelength is too short - driven element is about 1/2 wavelength. 1/4 wavelength is wrong. Option C (3/4 wavelength): Incorrect. 3/4 wavelength is too long - driven element is about 1/2 wavelength. 3/4 wavelength is wrong. Option D (1 wavelength): Incorrect. 1 wavelength is too long - driven element is about 1/2 wavelength. 1 wavelength is wrong.
Exam Tip
Yagi driven element length = 1/2 wavelength. Think 'D'riven 'E'lement = 'D'ipole 'E'lement = '1'/2 wavelength. Driven element is typically about 1/2 wavelength, slightly shorter than resonant. Not 1/4, not 3/4, not 1 wavelength - just 1/2 wavelength.
Memory Aid
Yagi driven element length = 1/2 wavelength. Think 'D'riven 'E'lement = 'D'ipole 'E'lement. Driven element is typically about 1/2 wavelength, slightly shorter than resonant. Fundamental Yagi design.
Real-World Example
A Yagi antenna: The driven element is approximately 1/2 wavelength long (slightly shorter than resonant due to element interactions). It's similar to a dipole - the driven element is the active element that's fed. This is fundamental Yagi design - driven element is about 1/2 wavelength.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G9C
Reference: 2023-2027 Question Pool · G9 - Antennas and Feed Lines
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G9C topic.