1. A rule of thumb for air compressor output for each input horsepower is:

  1. 2 scfm @ 100 PSI
  2. 3 scfm @ 100 PSI
  3. 4 scfm @ 100 PSI

2. Large air compressors load and unload as pressure drops and builds. Small air compressors:

  1. do the same.
  2. never build enough pressure.
  3. turn on at a minimum pressure and off at a maximum pressure.

3. A hydraulic pump produces:

  1. flow in gallons per minute (gpm).
  2. pressure in pounds per square inch (psi).
  3. both of the above.

4. A positive-displacement pump:

  1. cannot turn if the outlet is blocked.
  2. can turn with the outlet blocked.
  3. can only turn with the outlet blocked.

5. Gear pumps:

  1. can be variable volume.
  2. cannot be variable volume.
  3. can be pressure compensated.

6. Vane pumps:

  1. can be variable volume.
  2. cannot be variable volume.
  3. cannot be pressure compensated.

7. Piston pumps .

  1. can be variable volume.
  2. cannot be variable volume.
  3. cannot be pressure compensated.

8. An open-center circuit:

  1. blocks pump flow in the center condition.
  2. does not have a center condition.
  3. allows pump flow to go to tank in center condition.

9. A closed-center circuit:

  1. blocks pump flow in the center condition.
  2. does not have a center condition.
  3. allows pump to go to tank in center condition.
10. The symbol at right is a:
  1. pressure-compensated variable-volume pump.
  2. fixed-volume pump.
  3. bi-directional pump.


11. While the input shaft of a bi-directional pump is turning in one direction of rotation, it:

  1. can move fluid from either port.
  2. can only move fluid from one port.
  3. must have a suction line hooked to tank.

12. Wobble-plate piston pumps:

  1. must rotate in the opposite direction to reverse flow.
  2. can reverse flow while turning the same way.
  3. cannot reverse flow at anytime.

13. Swash-plate piston pumps:

  1. have moveable or fixed-angle swash plates.
  2. are always bi-directional.
  3. can only move fluid one way.

14. Bent-axis pumps :

  1. cannot be fixed volume.
  2. operate better at higher vacuum inlet.
  3. cannot be bi-directional flow.

15. Load-sensing pumps:

  1. operate at load pressure plus load-sense bias spring pressure.
  2. operate at compensator pressure at all times.
  3. cannot be variable volume.

16. Horsepower- and torque-limiting pumps:

  1. use extra horsepower all the time.
  2. use minimum horsepower all the time.
  3. never use more than a preset horsepower regardless of pressure.

17. Pump shaft alignment is not important at any time.

  1. True
  2. False

18. Closed-loop circuits:

  1. use a makeup pump to keep the loop full.
  2. must have extra large flow lines to keep the pump from cavitating.
  3. cannot reverse the direction of an actuator.

19. A pump-motor adapter is:

  1. a device to keep the pump from cavitating.
  2. a unit to match pump horsepower to motor horsepower.
  3. a device to directly attach a pump to an electric motor.

20. Cavitation is caused by:

  1. too little fluid volume at the pump inlet.
  2. too much fluid volume at the pump inlet.
  3. too much fluid volume at the pump outlet.