A car uses power ofhp for a one hour in a round trip. Thermal efficiency ofcan be assumed? Find the change in entropy if we assume ambient at 20°C.
a) 354.1 kJ/K
b) 654.1 kJ/K
c) 254.1 kJ/K
d) 554.1 kJ/K
Q.2.
If heat Q flows reversibly from the system to the surroundings at To, what will be the effect on entropy?
a) entropy of the system is reduced by Q/To
b) system has lost entropy to the surroundings
c) entropy increase of the surroundings is Q/To
d) all of the mentioned
Q.3.
The entropy of any closed system can increase in which of the following way?
a) dissipative effects or internal irreversibilities
b) by heat interaction in which there is entropy transfer
c) both of the mentioned
d) none of the mentioned
Q.4.
A hot metal piece is cooled rapidly to 25°C, removingkJ from the metal. Calculate the change of entropy if saturated liquid R-at −20°C absorbs the energy so that it becomes saturated vapor.
a) 0.950 kJ/K
b) 7.950 kJ/K
c) 3.950 kJ/K
d) 5.950 kJ/K
Q.5.
The entropy change of a system between two identifiable equilibrium state is ___ when the intervening process is reversible or change of state is irreversible.
a) depends on the process
b) different
c) same
d) none of the mentioned
Q.6.
When work is dissipated into internal energy, what is the change in the disorderly motion of molecules.
a) increases
b) remains the same
c) decreases
d) none of the mentioned
Q.7.
Which of the following is an example of low grade energy?
a) heat from combustion of fossil fuel
b) heat or thermal energy
c) heat from nuclear fission or fusion
d) all of the mentioned
Q.8.
The available energy of a system ___ as its temperature or pressure decreases and approaches that of the surroundings.
a) remains constant
b) increases
c) decreases
d) none of the mentioned
Q.9.
Which of the following is true?
a) Q for reversible < Q for irreversible and work for reversible < work for irreversible
b) Q for reversible > Q for irreversible and work for reversible < work for irreversible
c) Q for reversible < Q for irreversible and work for reversible > work for irreversible
d) Q for reversible > Q for irreversible and work for reversible > work for irreversible
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