Which device records the number of occurrences of a signal?

• A. Accumulator
• B. Digital output
• C. Pseudopoint
• D. Pulse width modulation

Answer: (A)

The key idea is recording a running total by accumulating each event. An accumulator stores a number that increases every time the signal occurs, giving you a tally of how many times that event happened. In this context, each detected pulse is added to the stored value, so the final number reflects the total occurrences over the period you're observing.

Digital output just shows a high/low state and doesn’t keep a running count. Pulse width modulation controls the average power by adjusting the duty cycle, not counting events. A pseudopoint isn’t a standard device for tallying occurrences. So the accumulator uniquely serves the purpose of recording how many times the signal has occurred.