Which statement about a hydraulic system is accurate?

• A. If you double the piston area while keeping pressure constant, output force stays the same.
• B. If you double piston area while keeping pressure constant, output force doubles.
• C. Pressure is independent of piston area and does not affect force.
• D. Hydraulic systems work without fluids.

Answer: (B)

In a hydraulic system, the output force on a piston is the product of the pressure in the fluid and the piston’s area (F = P × A). If you keep the pressure constant and double the piston area, the output force doubles as a direct result of that relationship. The fluid transmits the same pressure to every connected piston, so increasing the area on one piston increases the total force that piston can exert without changing the pressure.

This is why the statement about doubling the output force when the piston area is doubled under constant pressure is the accurate one. The other ideas contradict how force depends on area under a given pressure, or ignore the role of the hydraulic fluid in transmitting that pressure.