3-45. Refer to figure 6-28 in your textbook. Which  statement relative  to  the  operation  of  this valve is false? 1. The upper poppet is controlled by the inside cam 2. Fluid flow to the return line is controlled by the lower poppet 3. Fluid  flow  from  the  pressure line is controlled by the upper  poppet 4. The  lower  poppet  is  unseated by the outside cam to allow the fluid to flow into the cylinder  and  actuate  the piston 3-46. When the pilot chamber of the three-way,   poppet-type,   normally closed  directional  control  valve is pressurized,    fluid  flows  from the  actuating  cylinder  through the valve and out the exhaust port . 1. True 2. False 3-47. Which  four-way  valves  are actuated by cams? 1. Rotary spool 2. Poppet 3. Sliding spool 4. All of the above 3-48. Which  type  of  valve  is  considered most  trouble  free  of  all  four-way valves? 1. Poppet 2. Rotary spool 3. Sliding spool 4. Cam  operated 3-49. Which  of  the  following  represents the flow of fluid as illustrated in figure 6-34, view B in your textbook? 1. 2. 3. 4. Learning  Objective: Recognize required   characteristics, functions, types,  and  materials of  sealing  devices  used  in  fluid power systems. 3-50. Suitable  packing  devices  for fluid  power  systems  are  made  from materials  that  possess  which  of the  following  characteristics? 1. Compatibility  with  fluids used in the systems 2. Effective  sealing  ability 3. Durability 4. All of the above 3-51. The term   “sealing devices”    is a classification  applicable  to packing  materials  used  to  provide an  effective  seal  between  which of the following parts? 1. Two moving parts 2. Two  stationary  parts 3. A moving part and a stationary  part 4. All of the above parts combinations 3-52. No  internal  leakage  should  be allowed to occur within a hydraulic  power  system  because  of the  resulting  loss  in  system efficiency. 1. True 2. False 3-53. Which  of  the  following  factors is/are  used  in  determining  the material  used  as  a  sealing  device for  a  particular  application? 1. Location of the seal 2. Storage of the seal 3. Both 1 and 2 above 4. Type of motion 3-54. Cork is suitable for use as gaskets because of which of the following   characteristics? 1. Its  resiliency 2. Its  flexibility 3. Its  compressibility 4. All of the above 21