To continue evacuating a chamber indefinitely without requiring infinite growth, a compartment of the vacuum can be repeatedly closed off, exhausted, and expanded again. This is the principle behind positive displacement pumps, like the manual water pump for example. Inside the pump, a mechanism expands a small sealed cavity to create a vacuum. Because of the pressure differential, some fluid from the chamber (or the well, in our example) is pushed into the pump's small cavity. The pump's cavity is then sealed from the chamber, opened to the atmosphere, and squeezed back to a minute size. COUNT 4
QSN1 Repeatedly closing off a compartment of a vacuum allows what? ANS1 continue evacuating a chamber indefinitely without requiring infinite growth QSN2 How is a vacuum created inside of a manual water pump? ANS2 a mechanism expands a small sealed cavity QSN3 Why is fluid in a manual pump pushed into the pumps cavity when a small sealed cavity is expanded? ANS3 Because of the pressure differential QSN4 What are pumps based off principle of sealed compartment pulling,pushing and expanding called? ANS4 displacement pumps