G9D10: Electrically small loop: In which direction or directions does an

Q: In which direction or directions does an electrically small loop (less than 1/10 wavelength in circumference) have nulls in its radiation pattern?

The correct answer is B: Broadside to the loop. The correct answer is B: Broadside to the loop. The direction or directions in which an electrically small loop (less than 1/10 wavelength in circumference) has nulls in its radiation pattern is broadside to the loop. Small loops have nulls (minimum radiation) broadside (perpendicular) to the plane of the loop. For amateur radio operators, this is important for direction finding. Understanding this helps when using loop antennas.

Updated: Dec 9, 2025 | Source: 2023-2027 Question Pool | Topic: G9D

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In which direction or directions does an electrically small loop (less than 1/10 wavelength in circumference) have nulls in its radiation pattern?

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Deep Dive: G9D10

The correct answer is B: Broadside to the loop. The direction or directions in which an electrically small loop (less than 1/10 wavelength in circumference) has nulls in its radiation pattern is broadside to the loop. Small loops have nulls (minimum radiation) broadside (perpendicular) to the plane of the loop. For amateur radio operators, this is important for direction finding. Understanding this helps when using loop antennas.

Why Other Answers Are Wrong

Option A: Incorrect. Nulls aren't in the plane of the loop - they're broadside (perpendicular) to the plane. In the plane is wrong. Option C: Incorrect. Nulls aren't both broadside and in the plane - they're only broadside. Both is wrong. Option D: Incorrect. Small loops aren't omnidirectional - they have nulls broadside. Omnidirectional is wrong.

Exam Tip

Small loop nulls = broadside to the loop. Think 'S'mall 'L'oop = 'S'ignal 'L'owest 'B'roadside. Small loops have nulls (minimum radiation) broadside (perpendicular) to the plane of the loop. Not in the plane, not both, not omnidirectional - just broadside.

Memory Aid

Small loop nulls = broadside to the loop. Think 'S'mall 'L'oop = 'N'ulls 'B'roadside. Small loops have nulls (minimum radiation) broadside (perpendicular) to the plane of the loop. Important for direction finding.

Real-World Example

An electrically small loop antenna: The loop has nulls (minimum radiation) broadside to the loop - perpendicular to the plane of the loop. This is why loops are used for direction finding - you can rotate the loop to find the null direction. Small loops have nulls broadside - this is their radiation pattern characteristic.

Source & Coverage

Question Pool: 2023-2027 Question Pool

Subelement: G9D

Reference: 2023-2027 Question Pool · G9 - Antennas and Feed Lines

Key Concepts

Electrically small loop Nulls Broadside to the loop Radiation pattern

Verified Content

Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G9D topic.