A heat engine with a thermal efficiency of 45% produces 880 kJ of work. Heat transfer to the engine is from a reservoir at a temperature of 550 K, and the heat transfer from the

engine to the surrounding air is at 300 K.
a) Determine the heat transfer to and from the heat engine.
b) Find the maximum efficiency of the heat engine.

What precautions should you take to prevent injuries when dealing with heavy loads?

Which of the following ziegler nichols tuning methods the response of the controller to a step input should exhibit an s-shaped curve? a)-open loop mode b)-closed loop mode c)-both modes (open & closed) d)-none of the modes (open & closed)

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.