🔍 Key Concepts

• Hydraulic cylinder retraction with no external load on the rod • Relationship between pressure and resistance to flow in a hydraulic system • How return flow to the reservoir behaves when there is (or is not) a restriction

💭 Think About

• Ask yourself: what actually creates pressure in a hydraulic line—moving fluid by itself, or resistance to that movement? • During retraction with no load, what is happening to the oil at the cap end—does it push against anything, or does it simply flow back to tank through a (normally) low‑pressure return line? • If speed of retraction increases but the return line and valves are still wide open, how does that affect the pressure on the returning oil?

✅ Before You Answer

• Verify what is meant by "without an applied load" on the cylinder rod and how that affects required pressure. • Consider whether the return line to tank is assumed to be essentially unrestricted and at low/near-atmospheric pressure in basic theory problems. • Check whether any of the answer choices incorrectly suggest that pressure must always vary directly or inversely with speed or flow rate, even when there is no resistance.