What device measures current, voltage, and resistance in an aircraft system?

• A. Oscilloscope
• B. Multimeter
• C. Fuel Flow Meter
• D. Pressure Gauge

Answer: (B)

The device that measures current, voltage, and resistance in an aircraft system is known as a multimeter. This instrument is essential for both troubleshooting and routine maintenance of electrical systems. A multimeter allows technicians to obtain accurate measurements of electrical parameters, which is crucial for diagnosing issues within circuits or ensuring that systems are operating within specified limits.

A multimeter can usually be switched between different modes to measure the specific electrical property of interest. In current measurement mode, it can determine how much electric current is flowing through a circuit. When set to voltage measurement, it can assess the potential difference between two points. Additionally, in resistance mode, it provides the value of resistance in ohms, helping to identify issues like shorts or opens in the wiring.

Other devices listed serve different purposes. For instance, an oscilloscope is primarily used to visualize electrical signals over time, which helps in understanding signal shape and frequency but does not directly measure resistance. A fuel flow meter is designed to measure the flow rate of fuel in systems, and a pressure gauge monitors pressure levels in various systems but does not relate to electrical measurements. Therefore, the multimeter is the versatile tool needed for comprehensive electrical diagnostics in aircraft systems.