Which describes the two categories of hydraulic pumps?

• A. Power Pumps-Driven by Power Sources; Hand Pumps-Operated Manually
• B. Gear Pumps and Vane Pumps
• C. Centrifugal Pumps and Positive-Displacement Pumps
• D. Axial Flow Pumps and Radial Pumps

Answer: (A)

The concept being tested is how hydraulic pumps are categorized by how they are powered. Pumps fall into two broad groups: power-driven pumps that operate from the aircraft’s power source (engine or electrical power) and hand-operated pumps that you run manually. This distinction matters because it directly affects operation, maintenance, and failure scenarios—normal operations rely on power-driven pumps, while hand pumps provide a manual backup when power is unavailable.

The other options describe specific pump types or configurations (gear vs vane, centrifugal vs positive-displacement, axial vs radial) rather than the two broad power-based categories. Those distinctions are real, but they aren’t the two overarching categories used in this context.