In practical digital-circuit troubleshooting, a handheld multimeter is best used to measure which quantities on a static or slowly changing node?

Introduction / Context:
A multimeter is a fundamental tool for electronics work, but it is limited by measurement speed and display type. Knowing what it measures well in digital circuits prevents misinterpretation and speeds diagnosis.

Given Data / Assumptions:

• Standard DMM with DC/AC voltage, resistance, and current ranges.
• Digital signals may be static levels (logic HIGH/LOW) or fast pulses.
• We seek what a DMM accurately measures in this context.

Concept / Approach:
Multimeters excel at scalar measurements: DC voltage, average AC voltage (within bandwidth limits), and resistance of unpowered networks. They cannot observe rapid timing parameters such as pulse width or duty cycle and are not ideal for fast current pulses without specialized shunts and bandwidth.

Step-by-Step Solution:
For a logic rail, use DC volts to confirm nominal level (e.g., 3.3 V or 5 V).For pull-ups/pull-downs, power off and measure resistance to confirm value and continuity.Avoid using a DMM to measure pulse widths; use a scope or logic analyzer.

Verification / Alternative check:
Manufacturers specify DMM update rates (often a few readings per second) and limited AC bandwidth, confirming unsuitability for timing measurements but reliability for DC voltage and resistance checks.

Why Other Options Are Wrong:

• Pulse width / pulse trains: Require time-domain instruments (oscilloscope, logic analyzer).
• Current: While DMMs can measure current, inserting in series can disturb circuits; it is not the typical quick check in digital IC debugging.

Common Pitfalls:

• Attempting to infer duty cycle from an averaged DMM reading; results are ambiguous.
• Measuring resistance on a live circuit leads to incorrect readings and potential damage.

Final Answer:
voltage or resistance