Here are the correct answers and explanations for each question:

1. Multifunction data acquisition boards usually have the following subsystems:
   • Correct Answer: All of the other systems mentioned
   • Explanation: Multifunction data acquisition boards typically integrate pulse generation, analog input/output, and digital input/output capabilities to support various signal acquisition and generation tasks.

2. To properly acquire a signal containing frequencies up to 100 Hz, the sampling frequency should be:
   • Correct Answer: Above 200 Hz
   • Explanation: According to the Nyquist theorem, the sampling frequency must be at least twice the highest frequency of the signal to avoid aliasing, so a sampling frequency greater than 200 Hz is required.

3. When the sampling frequency is too low and no anti-aliasing filter is used:
   • Correct Answer: Certain high frequencies will alias (will show up in a spectrum but at a lower frequency)
   • Explanation: Aliasing occurs when higher frequency components of a signal appear as lower frequency components due to undersampling.

4. Aliasing can be easily removed after it has already occurred during data acquisition:
   • Correct Answer: False
   • Explanation: Once aliasing has occurred, it is impossible to distinguish between true signal components and aliased components, making post-acquisition correction unfeasible.

5. The Nyquist frequency equals:
   • Correct Answer: ½ Sampling frequency
   • Explanation: The Nyquist frequency is defined as half of the sampling frequency and represents the highest frequency that can be accurately sampled without aliasing.

Do you need more clarification on any specific topic or calculation?

Here are 5 questions for deeper exploration:

1. What is the role of anti-aliasing filters in data acquisition systems?
2. How does oversampling improve signal quality in data acquisition?
3. Can you explain the relationship between Nyquist frequency and signal bandwidth?
4. How does pulse generation benefit data acquisition systems in real-world applications?
5. What are the consequences of incorrect sampling rates for digital systems?

Tip: Always apply an anti-aliasing filter before sampling to ensure accurate signal acquisition.