Answer Happy

please help me with number 1 2 and 74
1. Under which one of the following conditions would a Carnot heat engine be 100% efficient? A) The engine uses no heat. B) The engine does no work. C) The engine can be operated in reverse. D) The engine discharges heat at 0 K. 2. Which one of the following statements best describes the operation of a heat engine? A) A heat engine performs work and generates an equal amount of heat in a cyclic process. B) A heat engine transfers heat from a lower temperature reservoir to a higher temperature reservoir through work performed on the system. C) A heat engine uses input heat to perform work and rejects excess heat to a lower temperature reservoir D) A heat engine transfers heat from a higher temperature reservoir to a lower temperature reservoir through work performed on the system. (3) 74. A Carnot engine uses hot and cold reservoirs that have temperatures of 1684 and 842 K, respectively. The input heat for this engine is (Qhl. The work delivered by the engine is used to operate a Carnot heat pump. The pump removes heat from the 842-K reservoir and puts it into a hot reservoir at a temperature I'. The amount of heat removed from the 842-K reservoir is also Qul. Find the temperature I'. (6) )