🔍 Key Concepts
• Difference between voltage, current, and resistance measurements
• How an open circuit appears electrically in a winding
• Typical use of each instrument: potentiometer, ohmmeter, wattmeter, ammeter
đź’ Think About
• If a field winding is suspected to be open, what electrical property are you trying to check: current, voltage, power, or continuity/resistance?
• Which of the listed instruments is specifically designed to show whether a circuit path is continuous or broken?
• For each instrument, ask yourself: would it be connected in series or parallel, and what would its reading look like if the winding were open?
âś… Before You Answer
• Know that an open circuit in a winding means infinite resistance and zero current.
• Match each device to its primary measurement: ohms, amps, watts, or volts.
• Be clear on which instrument is commonly used for continuity tests in DC circuits.