🔍 Key Concepts

• Digital logic levels (what voltages represent logic 0 and logic 1) • How to stimulate inputs and observe outputs in a digital circuit • Why floating (open) inputs or continuous analog variation are generally bad practice in digital troubleshooting

💭 Think About

• In a healthy digital circuit, what should happen at the output if you intentionally change a valid logic level at the input? • Which choice describes using proper, defined logic 0 / logic 1 levels instead of leaving inputs open or sweeping them like an analog signal? • Which methods in the options could create unreliable or undefined logic states in a digital circuit?

✅ Before You Answer

• Make sure the method uses valid digital logic levels (only proper 0 or 1, not a smooth analog ramp) • Avoid any option that relies on all inputs grounded or all inputs open as a universal test – is that realistic for most digital circuits? • Choose the option that actively changes input states and looks for corresponding output changes, which is the core of digital troubleshooting.