5-47. Unusual  random  EMI  problems  in equipment  can  sometimes  be  caused by a defective line filter or unusually  large  voltages  on  power lines. 1. True 2. False 5-48. Control of EMI at a shore–based installation  requires  which  of  the following  factors  to  be  considered in addition to those that apply to shipboard   installation? 1. Shore  power 2. Site  location 3. Soil  Quality 4. Both 2 and 3 above 5–49. Which  of  the  following  precautions for EMI, if any, may be required at shore–based  equipment  sites  near industrial   facilities? 1. Shielding  may  be  needed  around especially  sensitive  pieces  of equipment 2. Additional  line  filters  and regulators  for  power  lines  may be needed to reduce EMI and provide  line  power  within specifications 3. Both 1 and 2 above 4. None 5–50. Which  of  the  following  statements is  correct  concerning  soil  quality at  shore–based  equipment  sites? 1. Soil with a good conduction will  cause  EMI  problems  because the soil will act as an antenna 2. A  system-ground  bus  is  usually attached to a grounding rod driven into the soil 3. Soil that is dry, sandy, and rocky is preferable to other types  of  soil  because  grounding problems  are  minimal 5-51. EMI  surveys  are  conducted  to distinguish  which  equipment  is affected by EMI and to determine the extent of the interference. In which  of  the  following  situations should an EMI survey be required or requested? 1. When a ship is newly constructed 2. When a ship receives an overhaul or major repair work that  changes  its  electro- magnetic   confiquration 3. When EMI is affecting the ship’s  equipments  and  ship’s force  and  assistance  personnel cannot  locate  the  source 4. All of the above 5-52. Detailed  information  on  EMI  surveys and reports may be found in which of  the  following publications/instructions? 1. OPNAVINST  5310.19 2. OPNAVINST  4790.4 3. MIL–STD-1605 4. SPCCINST  4441.170 5–53. When an EMI test plan is prepared, which  of  the  following  information should  be  provided? 1. The number of items of equipment 2. The  positions  to  be  monitored 3. The  approximate  time  the  survey should take 4. All of the above 5–54. Which phase of an EMI survey test phases  consists  of  operating certain  active  electronic  equipment while  receivers  and  susceptible equipment  are  monitored  for  EMI? 1. Phase I 2. Phase II 3. Phase III 4. Phase IV 35