Which term is a remote instrument indicating system?

• A. Solenoid
• B. Transformer
• C. Synchro System
• D. Tachometer

Answer: (C)

Remote instrument indicating systems convey machine position or status to a distant indicator. The Synchro System is built for this purpose. A synchro transmitter attached to the machine generates a rotating magnetic field whose angle represents the machine’s position. A synchro receiver at the control panel picks up that field and drives a remote indicator, giving an accurate readout at a distance. This setup makes it ideal for tasks like synchronizing generators, where you need to see the exact position remotely. Solenoids are used for linear motion, transformers change voltage/current levels, and tachometers measure speed. None of those provide the direct, angle-based remote indication that a synchro system does.