Which term refers to a device that converts a small movement into a greater movement or force?

• A. Servo
• B. Solenoid
• C. Tachometer
• D. Transformer

Answer: (A)

A servo is an actuator system that uses a motor, gearing, and feedback to control motion. The small input command is transformed by the gear train into a precise, often amplified output movement or torque, all guided by feedback to reach and hold the desired position. This combination of controlled movement with amplification explains why it’s the best fit for "converting a small movement into a greater movement or force."

A solenoid is a simple on/off device that moves a plunger in or out when energized, without feedback or amplification. A tachometer is a speed sensor, not an actuator. A transformer changes electrical energy levels and has no mechanical movement.