*Question G9D10:
In which direction or directions does an electrically small loop (less than 1/10 wavelength in circumference) have nulls in its radiation pattern?*  

*Correct Answer is  B: Broadside to the loop*  

### AI Response: (may contain errors)  

An electrically small loop antenna, defined as having a circumference of less than 1/10 wavelength, exhibits specific radiation characteristics. 

### Correct Answer: Broadside to the loop

- **Explanation**: 
  - An electrically small loop has its maximum radiation in the plane perpendicular to the loop (broadside). This means that the strongest radiation occurs at angles 90 degrees to the loop's plane. 
  - The nulls, or points of minimal radiation, occur along the axis of the loop, which is the direction parallel to the plane of the loop.

### Why the Other Choices are Incorrect:

- **A: In the plane of the loop**: 
  - This choice is incorrect because the radiation is strongest broadside to the loop, not in the plane of the loop. The loop does not radiate effectively in the direction of its own plane.

- **C: Broadside and in the plane of the loop**: 
  - This choice is incorrect because while the loop does have a broadside radiation pattern, it does not radiate effectively in the plane of the loop. The nulls are specifically along the axis of the loop, not in the plane.

- **D: Electrically small loops are omnidirectional**: 
  - This choice is incorrect because electrically small loops are not omnidirectional. They have a specific radiation pattern with nulls and maximum radiation directions. Omnidirectional antennas radiate equally in all directions, which is not the case for small loops.

### Useful Rules of Thumb:

- **Radiation Pattern**: For electrically small loops, the radiation pattern is primarily toroidal (doughnut-shaped) with maximum radiation broadside to the loop.
- **Nulls**: The nulls occur along the axis of the loop, where the radiation is minimal.

Understanding these characteristics will help you answer questions related to antenna patterns effectively on the Extra Class exam.