Which item is listed as a prime mover for pumps?

• A. Gas turbines
• B. Electric motors
• C. Steam generators
• D. Internal combustion engines

Answer: (B)

A prime mover is the device that provides the initial mechanical energy to turn the pump shaft. Electric motors are the most common prime mover for pumps because they directly convert electrical energy into rotational motion, offering simple, reliable operation and easy control through variable-frequency drives. They start smoothly, respond quickly to speed changes, and are compact, economical, and clean compared with combustion-based options.

Other choices can drive pumps in some setups, but they come with more complexity or drawbacks. Gas turbines and internal combustion engines require fuel and produce exhaust and more vibration; steam generators themselves don’t directly drive a pump without a turbine or other machinery to convert the steam’s energy into rotation. That’s why electric motors are listed as the prime mover for pumps in typical applications.