Chapter 7, Problem 7.49CU

Multiple choice Questions Question No. 2: When a system is taken from state A to state B through a reversible path 1 and again the system is taken to its initial state A from B through different reversible path 2, then what will be the effect on entropy? a.entropy increasesb.entropy decreasesc. entropy remains constantd. none of the above

What does the exergy principle state? The exergy of an isolated system can never decreases, but always increases O The exergy of an isolated system can never increases, but always decreases O The exergy of an isolated system can either increases or decreases O None of the above

For the same initial and final states the change of entropy for constant .10 * volume process is greater than that for constant pressure process False True O According to the first law of thermodynamic the heat engine can.11 produce work less to the gross heat supplied False O True According to the second law of thermodynamic the heat engine can .12 * produce work equal to the gross heat supplied False O True

Define the Mechanisms of exergy transfer.

3.1 For discussion: (a) Is it possible for exergy to be negative? Discuss. (b) Consider an evacuated space with volume V as the system. Eval- uate its exergy and discuss. PH associated with (c) Is it possible for the specific physical exergy e' a stream of matter to be negative? Discuss.

At a pressure of 1 bar, a temperature of 17 °C and a mass flow of 0.3 kg/s, air enters a stable insulated compressor and exits at 3 bar, 147 °C. Determine the power required by the compressor and the exergy destruction in kW. Express the exergy disappearance as a percentage according to the power required by the compressor. Changes in kinetic and potential energy will be neglected. dead state; T0=17 °C, P0=1 bar

3. A mole of an ideal, diatomic gas undergoes isothermal, reversible expansion from 1.0 cubic diameter to 10.0 cubic diameter at 100 degrees celsius. if the same gas undergoes irreversible expansion against a constant pressure of 1.00 bar, which of the following would change? a. internal energy b. entropy c. free energy d. enthalpy

Apply exergy balance to closed systems and control volumes.

Relate between the entropy with the Clausius statement of the second thermodynamics law. [Note: The answer must include appropriate equations]