🔍 Key Concepts
• Difference between RMS (root mean square), peak, and average values of AC current
• What a typical analog or digital AC ammeter is calibrated to show
• Relationship between AC heating effect and equivalent DC current value
💭 Think About
• When we say an AC ammeter reads the same as a DC ammeter for the same heating effect in a resistor, which quantity of the AC waveform is being measured?
• Does common shipboard electrical equipment care more about the instantaneous peak of the current, or about the equivalent power/heat delivered over time?
• Which of the listed quantities (TRM, RMS, peak, average) is standard for specifying AC supply values like 120 V or 230 V?
✅ Before You Answer
• Be clear on the definition of RMS value versus peak value for a sine wave
• Confirm what quantity a standard commercial AC ammeter (without any special markings) is calibrated to indicate
• Note whether TRM is a standard electrical measurement term compared to RMS