Resolution is defined as:

• A. The smallest change an input signal value that can be sensed
• B. The maximum signal level
• C. The sampling rate
• D. The number of input channels

Answer: (A)

Resolution describes the smallest increment of input value that the system can reliably distinguish. It depends on how many discrete levels the analog-to-digital converter can output (the number of bits) and the full-scale measurement range. The more bits, the finer the step between levels, and thus the finer the resolution. For example, a 12-bit ADC over 0–10 V gives about 10 V / 4096 ≈ 2.44 mV per step, so the smallest change you can detect is around that amount. This makes the option describing the smallest detectable change the correct definition. The maximum signal level refers to full-scale range, not the smallest discernible change. The sampling rate is about how often you sample over time, not how finely you resolve the value. The number of input channels deals with how many signals can be measured simultaneously, not resolution.