*Question E4B01:
Which of the following factors most affects the accuracy of a frequency counter?*  

*Correct Answer is  B: Time base accuracy*  

### AI Response: (may contain errors)  

To determine the accuracy of a frequency counter, the most significant factor is the time base accuracy. Here's a breakdown of why this is the correct answer and why the other options are less critical:

### Correct Answer: Time Base Accuracy (B)
- **Explanation**: The time base of a frequency counter is essentially the clock that determines how time is measured. If the time base is inaccurate, the frequency measurement will also be inaccurate. The frequency counter calculates frequency as the number of cycles per second, which directly relies on precise timing. Therefore, any error in the time base translates directly to an error in frequency measurement.

### Why the Other Choices Are Incorrect:
- **A: Input Attenuator Accuracy**  
  - While input attenuator accuracy can affect the signal level being measured, it does not directly impact the frequency measurement itself. It primarily influences the amplitude of the signal, not the timing.

- **C: Decade Divider Accuracy**  
  - The decade divider is used to reduce the frequency to a manageable level for counting. While its accuracy is important, it is secondary to the time base accuracy. If the time base is off, the counting process will still yield inaccurate results regardless of the divider's precision.

- **D: Temperature Coefficient of the Logic**  
  - The temperature coefficient refers to how the performance of electronic components changes with temperature. While this can affect the overall performance of the frequency counter, it is not as critical as the time base accuracy. The time base directly influences the fundamental measurement of frequency.

### Summary
In summary, the time base accuracy is the most crucial factor affecting the accuracy of a frequency counter because it directly influences how time is measured, which is essential for calculating frequency. The other factors, while they can have some impact, do not have the same level of direct influence on frequency measurement.