FAA Aviation Mechanic General (AMG)Fundamentals of Electricity and ElectronicsEasy
A technician is troubleshooting an aircraft electrical system and notes that the voltage measured across a specific component is 0 volts, while the current flowing through it is extremely high. Which type of circuit fault is most likely indicated by these readings?
- AShorted circuit
- BIntermittent fault
- CHigh resistance fault
- DOpen circuit
Show answer & explanationAnswer & explanation
Correct answer: A. Shorted circuit
A shorted circuit provides a path of very low resistance, causing a very high current flow and a voltage drop across the short that approaches zero. This aligns with the observed symptoms.
Why the other options are wrong
- B. An intermittent fault would show fluctuating readings, not consistently zero voltage with high current.
- C. A high resistance fault would cause a significant voltage drop and reduced current flow.
- D. An open circuit would result in no current flow and potentially a high voltage reading across the break.
Shorted Circuit
An electrical fault where current bypasses the intended path due to a low-resistance connection, often leading to excessive current and minimal voltage drop across the short.
- Low or near-zero resistance path.
- Results in very high current flow.
- Voltage drop across the short is minimal.
Memory trick: Open, Short, High-R: Three ways a circuit goes awry.