Circle the correct answers for the following multiple choice

Circle the correct answers for the following multiple choice problems and also enter the answer on the first page of the exam. A problem may have more than one correct answer. M.1 Which of the following statements are true regarding an internally reversible isothermal process? (a) The entropy change is always zero. (b) The entropy change can be only zero or increase. (c) The entropy change can be zero, increase or decrease. (d) There is insufficient information given to provide an answer. M.2 Which of the following statements are true regarding the entropy change of an isolated system during a process? (a) If the process is irreversible, the entropy will always increase (b) If the process is reversible, the entropy will remain constant. (c) If the process is reversible, the entropy will remain constant or decrease. (d) The entropy change depends on the state of the surroundings. M.3 Which of the following are means by which the efficiency of a Rankine cycle can be increased? (a) Increase the mass flow rate of the working fluid. (b) Decrease the compressor pressure. (c) Superheat the steam to a higher temperature. (d) Decrease the boiler pressure. M.4 Which of the following are characteristics of a reversible process? (a) Heat transfer occurs at an infinitesimal temperature difference. (b) No friction is involved in the process. (c) It is an isobaric (constant pressure) process. (d) It is a quasi-equilibrium process. M.5 Which of the following are possible means of energy transfer between two closed systems or a closed system and its surrounding? (a) Heat (b) Mass flow (c) Thermal efficiency (d) Work

Solution

M.1 a.) The entropy change is always zero.

M.2 a.) If the process is irreversible, the entropy will always increase.

        b.) If the process is reversible, the entropy will remain constant.

M.3 c.) Superheat the steam to a higher temperature.

M.4 d.) It is a quasi-equilibrium process.

M.5 a.) Heat d.) Work