7-43. 7-44. 7-45. 7-46. 7-47. 7-48. What is the approximate indicated horse- power  for  the  engine  at  2,500  rpm? 1. 200 hp 2. 216 hp 3. 232 hp 4. 247 hp Under  full  load  at  2,500  rpm,  the  average pressure exerted on a piston of the engine during each power stroke is 1. 17 1/3 psi 2. 52 psi 3. 104 psi 4. 208 psi What effect does a 4-psi drop in cylinder mean effective pressure have on the power developed by the engine at 2,500 rpm? 1. Fewer  decreases  since  cylinder  bmep exceeds 100 psi and engine speed drops 2. Power  decreases  since  cylinder temperature  drop  and  quality  of combustion  is  impaired 3. Fewer  increases  since  cylinder  bmep exceeds  100  psi  and  engine  speed rises 4. Power  increases  since  cylinder temperature  rises  and  quality of  combustion  improves Which  of  the  following  expressions  is used to compute brake horsepower at 2,500  rpm? 1. ihp - 32 2. ihp + 32 3. (ihp -   32)ihp 4. (ihp + 32)ihp The  approximate  brake  mean  effective pressure  at  2,000  rpm  is 1. 81 psi 2. 87  psi 3. 93 psi 4. 102 psi What is the engine's maximum mechanical efficiency? 1. 81.3% 2. 72.4% 3. 87.0% 7-49. What  is  the  approximate  mechanical efficiency  of  the  engine  when  operatinq under  half  load  at  2,000  rpm? 1. 72% 2. 81% 3. 84% 4. 87% 7-50. The maximum mechanical efficiency for this  engine  multiplied  by  104  psi be equivalent to bmep under which the  following  conditions? should of 1. Half  load  and  2,000  rpm Full  load  and  2,500  rpm No  load  and  2,500  rpm No  load  and  2,000  rpm 2. 3. 4. 7-51. Which of the following factors limit the power that each piston of the engine can develop  during  a  power  strike? 1. 2. Frictional  heat Scavenge   efficiency 3. Heat  losses  due  to  incomplete combustion 4. Each of the above 7-52. If  the  volumetric  efficiency  of  a  4- stroke  engine  is  50  percent,  the  amount of air drawn into a cylinder is 1. equal  to  the  amount  of  air  that  would enter the cylinder under ideal condi- tions 2. half  the  amount  of  air  consumed  by combustion 3. half  the  amount  of  air  that  would enter  the  cylinder  under  ideal conditions 4. twice  the  amount  of  air  consumed  by combustion 7-53. How  is  scavenge  efficiency  of  a  2-stroke cycle  engi ne determined? 1. By  measuring  the  air  required  for combustion 2. By  measuring  the  amount  of  burned gases  removed  from  the  cylinder 3. Both 2 and 3 above 4. By  measuring  the  amount  of  fresh  air entering  the  cylinder 4. 90.5% 46