Choose The Right Answer 1)Which single one of the following second law statement
ID: 1858814 • Letter: C
Question
Choose The Right Answer
1)Which single one of the following second law statements is incorrect ?
A.
Work must be input if energy is transferred from a cold body to a hot body
B.
The entropy of an isolated process must remain constant or rise
C.
The entropy of a hot object decreases as it cools
D.
Heat must be rejected from a heat engine
2)Select an acceptable paraphrase of the Kelvin-Planck statement of the second law
A.
No process can produce more work than the heat that it accepts.
B.
An engine cannot produce work without accepting heat
C.
An engine has to reject heat
D.
No engine can produce more work than the heat that it intakes
3) In a quasi-equilibrium process, which single one of the following is correct ?
A.
The pressure is everywhere constant at an instant
B.
The pressure varies with temperature
C.
The pressure force results in a positive work input
D.
The pressure remains constant
4) An inventor claims to extract 100 kJ of energy from 30 °C sea water at the surface and generate 7 kJ of heat while rejecting 93 kJ to a 10 °C stratum below the surface. The scheme fails because of which reason below ?
A.
The machine is a perpetual motion machine
B.
The temperature of the sea water is too low
C.
It violates the first law in some respect
D.
It violates the second law in some respect
5) Which of the following second law statements is incorrect ?
A.
The entropy of a hot copper block decreases as it cools
B.
Work must be input if energy is transferred from a cold body to a hot body.
C.
If ice is melted in water in an insulated container, the net entropy decreases.
D.
The entropy of an isolated system must remain constant or increase
6)Which single one of the following first-law statements is incorrect ?
A.
The net heat transfer equals the work output for an engine operating on a cycle.
B.
The heat transfer equals the enthalpy change for an adiabatic process
C.
The internal energy change equals the work of a system for an adiabatic process
D.
The heat transfer equals the quasiequilibrium work of a system for a constant-volume process in which the internal energy remains constant
The Rankine power cycle is an idealised cycle. Which single of the following is not one of the ideal assumptions ?
A.
Pipes connecting components are insulated
B.
Friction is absent
C.
Heat transfer does not occur across a finite temperature difference
D.
Pressure drops in pipes are neglected
7) The engines on a commercial jet aircraft operate on which one of the basic
cycles below ?
A.
Otto
B.
Brayton
C.
Carnot
D.
Rankine
8) With respect to a thermodynamic system, which single one of the following statements is correct ?

A.
Energy may be created by heat or destroyed by work
B.
Thermodynamic systems possess energy, heat and work
C.
Heat and work are boundary phenomena, systems possess energy, but not heat or work
D.
Heat and work are independent of the path a process takes
9) Which single statement below is incorrect ?
A.
Entropy is a measure of the quality or importance of energy
B.
The second law of thermodynamics says that energy of all kinds disperses or spreads out if it is not hindered from doing so
C.
Entropy change measures the rate at which work is done by a system as a function of time
D.
The Third Law states that the entropy of a pure substance approaches zero as the absolute temperature approaches zero
10) Which of the following statements about work for a quasi-equilibrium processs is incorrect ?
A.
Work is a path function
B.
The differential of work is inexact
C.
Work is the area under a curve on the P-T diagram
D.
Work is energy crossing a boundary
11) Which single one of the following statements is a correct definition of the Carnot Efficiency?
A. The efficiency of steam engines available when Sadi Carnot (1796-1832) was alive
B. The minimum efficiency expected of any heat engine when operating between two
thermal energy reservoirs
C. Exactly an efficiency of 66.666%
D. The greatest efficiency a heat engine can achieve when operating between a high
temperature and a low temperature thermal energy reservoir
A.
Work must be input if energy is transferred from a cold body to a hot body
B.
The entropy of an isolated process must remain constant or rise
C.
The entropy of a hot object decreases as it cools
D.
Heat must be rejected from a heat engine
Explanation / Answer
C.D.
A.
C.
C.