*Question E8A10:
What is the purpose of a low-pass filter used at the output of a digital-to-analog converter?*  

*Correct Answer is  C: Remove spurious sampling artifacts from the output signal*  

### AI Response: (may contain errors)  

A low-pass filter is used at the output of a digital-to-analog converter (DAC) primarily to remove spurious sampling artifacts from the output signal. Let's break down why this is the correct answer and why the other choices are incorrect:

1. **Correct Answer: C - Remove spurious sampling artifacts from the output signal**

   - **Explanation**: When a DAC converts a digital signal to an analog signal, it can introduce high-frequency components known as "sampling artifacts" or "aliasing." These are unwanted frequencies that result from the discrete nature of digital signals. A low-pass filter allows only the desired low-frequency components to pass through while attenuating these high-frequency artifacts, resulting in a cleaner analog signal.

2. **Incorrect Choices:**

   - **A: Lower the input bandwidth to increase the effective resolution**
     - **Explanation**: A low-pass filter does not affect the input bandwidth or the resolution of the DAC. Resolution is determined by the number of bits in the DAC, not by filtering.

   - **B: Improve accuracy by removing out-of-sequence codes from the input**
     - **Explanation**: A low-pass filter operates on the output signal, not the input. It does not correct or remove any errors in the digital input codes.

   - **D: All these choices are correct**
     - **Explanation**: Since choices A and B are incorrect, this option is also incorrect.

In summary, the primary role of a low-pass filter at the output of a DAC is to clean up the signal by removing high-frequency artifacts, ensuring that the output is a smooth and accurate representation of the intended analog signal.