[Master 2013]

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و لدي مسائل أرجو إفادتي بحلولها
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5 مسائل

المسالة الاولى:
A nuclear power station is designed to generate 1000 MW of electrical power.To do this it maintains a reservoir of superheated steam at a temperature of 400K.Waste heat from the reactor is transferred by a heat exchanger to circulating sea water at 300 K.what is the minimum possible rate of nuclear energy generation needed?????????

المسالة الثانية :
you are asked to design a refrigerated warehouse to maintain perishable food at a temperature of 5 C in an external environment of up to 30 C.the size of the warehouse and its degree of thermal insulation mean that the refrigeration plant must extract heat at a rate of 1000KW.As a first step you must supply the local electricity company with an estimate for the likely electrical consumption of the proposed warehouse .what value would you suggest as a working minimum???

المسالة الثالثة:
one mole of idealgas is maintained at a temperature T.


a/what is the minimum work needed to reduce its volume by a factor of e (=2.718)?


b\what is the entropy loss of the gas during this process?
المسالة الرابعة :

4/1 kg of water at 20C is placed in thermal contact with a heat reservoir at 80C .what is the entropy change of the total system (water plus reservoir)when equilibrium has been re-established?

المسالة الخامسة :

5/demonstrate that the entropy change for ᶯ moles of ideal gas can also be written as


Where T1,P1 andT2,P2 are the initial and final temperatures and pressures respectively and CP is the heat capacity at constant pressure.