Question 1

Which one of the following statements is not a consequence of the second law of thermodynamics?

Accepted Answer

A) The efficiency of any engine is less than 100%. 
B) The natural direction of heat flow is from hot to cold. 
C) A motor can operate using the atmosphere as a heat reservoir. 
D) Only reversible processes have a zero net entropy change for the universe. 
E) There is zero net entropy change for the universe in the operation of a real refrigerator. 
A) The efficiency of any engine is less than 100%. 
B) The natural direction of heat flow is from hot to cold. 
C) A motor can operate using the atmosphere as a heat reservoir. 
D) Only reversible processes have a zero net entropy change for the universe. 
E) There is zero net entropy change for the universe in the operation of a real refrigerator.

Question 2

An engine is used to lift a 2700-kg truck to a height of 3.0 m at constant speed. In the lifting process, the engine received 4.18 × 105 J of heat from the fuel burned in its interior. What is the efficiency of the engine?

Accepted Answer

A) 0.19 
B) 0.24 
C) 0.29 
D) 0.34 
E) 0.39 
A) 0.19 
B) 0.24 
C) 0.29 
D) 0.34 
E) 0.39

Question 3

In an isothermal process, 1.59 moles of an ideal gas is compressed to one-fifth of its initial volume at 285 K. What quantity of heat is added to, or removed from, the system during this process?

Accepted Answer

A) 133 J added 
B) 3020 J added 
C) 1070 J removed 
D) 6060 J removed 
E) 8880 J removed 
A) 133 J added 
B) 3020 J added 
C) 1070 J removed 
D) 6060 J removed 
E) 8880 J removed

Question 4

In which one of these processes will there be no net change in the entropy of the system?

Accepted Answer

A) the growth of a microorganism 
B) the fusion of a crystalline solid 
C) the heating of water in an open container 
D) the combustion of fuel in a machine engine 
E) the evaporation and condensation of benzene in a closed vessel 
A) the growth of a microorganism 
B) the fusion of a crystalline solid 
C) the heating of water in an open container 
D) the combustion of fuel in a machine engine 
E) the evaporation and condensation of benzene in a closed vessel

Question 5

A block that slides on a rough surface slows down and eventually stops. The reverse process never occurs. That is, a block at rest never begins to move and accelerate on a rough surface without the action of an external agent. The second situation is forbidden because it would violate

Accepted Answer

A) conservation of total energy. 
B) conservation of momentum. 
C) the first law of thermodynamics. 
D) the second law of thermodynamics. 
E) both the first and second laws of thermodynamics. 
A) conservation of total energy. 
B) conservation of momentum. 
C) the first law of thermodynamics. 
D) the second law of thermodynamics. 
E) both the first and second laws of thermodynamics.

Question 6

Complete the following statement: The first law of thermodynamics states that

Accepted Answer

A) heat is a form of energy. 
B) entropy is a function of state. 
C) the entropy of the universe is increasing. 
D) the change in the internal energy of a system is given by Q - W. 
E) no engine can be more efficient than a Carnot engine operating between the same two temperatures. 
A) heat is a form of energy. 
B) entropy is a function of state. 
C) the entropy of the universe is increasing. 
D) the change in the internal energy of a system is given by Q - W. 
E) no engine can be more efficient than a Carnot engine operating between the same two temperatures.

Question 7

If one complete cycle of a reversible process is carried out on a sample of an ideal gas so that its final state is the same as its initial state, which one of the following quantities is the only one which can be non-zero?

Accepted Answer

A) the change in volume of the sample 
B) the net heat absorbed by the sample 
C) the change in the entropy of the sample 
D) the change in temperature of the sample 
E) the change in the internal energy of the sample 
A) the change in volume of the sample 
B) the net heat absorbed by the sample 
C) the change in the entropy of the sample 
D) the change in temperature of the sample 
E) the change in the internal energy of the sample

Question 8

A Carnot engine has a heat input of 3700 J and heat exhaust of 1400 J. What is the ratio of the Kelvin temperature of the hot reservoir to that of the cold reservoir, TH/TC?

Accepted Answer

A) 3.6 
B) 0.38 
C) 1.6 
D) 0.62 
E) 2.6 
A) 3.6 
B) 0.38 
C) 1.6 
D) 0.62 
E) 2.6

Question 9

Under which one of the following conditions would a Carnot heat engine be 100% efficient?

Accepted Answer

A) The engine discharges heat at 0 K. 
B) The engine uses no heat. 
C) The engine does no work. 
D) The engine can be operated in reverse. 
E) The engine uses an ideal gas. 
A) The engine discharges heat at 0 K. 
B) The engine uses no heat. 
C) The engine does no work. 
D) The engine can be operated in reverse. 
E) The engine uses an ideal gas.

Question 10

A heat pump is found to remove 2400 J of heat from the exterior of a house and deliver 3500 J of heat to the interior of the house. What is the coefficient of performance of the heat pump?

Accepted Answer

A) 1.5 
B) 3.2 
C) 2.7 
D) 3.9 
E) 2.2 
A) 1.5 
B) 3.2 
C) 2.7 
D) 3.9 
E) 2.2

Question 11

A heat engine operates between a hot reservoir at 1500 K and a cold reservoir at 500 K. During each cycle, 1.0 × 10S1U1P15S1S1P0 J of heat is removed from the hot reservoir and 5.0 × 10S1U1P14S1S1P0 J of work is performed.
-What is the actual efficiency of this engine?

Accepted Answer

A) 0.15 
B) 0.34 
C) 0.50 
D) 0.67 
E) 0.81 
A) 0.15 
B) 0.34 
C) 0.50 
D) 0.67 
E) 0.81

Question 12

A heat engine operates between a hot reservoir at 1500 K and a cold reservoir at 500 K. During each cycle, 1.0 × 10S1U1P15S1S1P0 J of heat is removed from the hot reservoir and 5.0 × 10S1U1P14S1S1P0 J of work is performed.
-Determine the Carnot efficiency of this engine.

Accepted Answer

A) 0.15 
B) 0.34 
C) 0.50 
D) 0.67 
E) 0.81 
A) 0.15 
B) 0.34 
C) 0.50 
D) 0.67 
E) 0.81

Question 13

Beneath the moveable piston in the drawing,2.25 moles of a monatomic ideal gas is enclosed at 314 K. The initial volume of the gas is 3.0 m3. The gas is compressed isothermally to a final volume of 1.0 m3. How much heat is removed from the gas during this process?

Accepted Answer

A) -6450 J 
B) -4300 J 
C) -2900 J 
D) -1450 J 
E) zero joules 
A) -6450 J 
B) -4300 J 
C) -2900 J 
D) -1450 J 
E) zero joules

Question 14

A fixed amount of ideal gas is compressed adiabatically. Which entry in the table below correctly indicates the sign of the work done, the change in the internal energy, and the heat exchanged with the environment? work done change in internal energy heat exchanged

Accepted Answer

A) positive negative zero 
B) negative zero positive 
C) negative negative zero 
D) positive positive zero 
E) negative positive zero 
A) positive negative zero 
B) negative zero positive 
C) negative negative zero 
D) positive positive zero 
E) negative positive zero

Question 15

An ideal gas is taken from state A to state B through process shown on the pressure-volume graph. How much heat is added to the gas in this process?

Accepted Answer

A) zero joules 
B) 1.0 × 104 J 
C) 2.4 × 104 J 
D) 6.0 × 104 J 
E) This cannot be determined since n and T are not specified. 
A) zero joules 
B) 1.0 × 104 J 
C) 2.4 × 104 J 
D) 6.0 × 104 J 
E) This cannot be determined since n and T are not specified.

Question 16

An ideal monatomic gas expands isothermally from state A to state B. The gas then cools at constant volume to state C. The gas is then compressed isobarically to D before it is heated until it returns to state A.  
-What is the pressure of the gas when it is in state B?

Accepted Answer

A) 5 atm 
B) 10 atm 
C) 20 atm 
D) 25 atm 
E) 30 atm 
A) 5 atm 
B) 10 atm 
C) 20 atm 
D) 25 atm 
E) 30 atm

Question 17

Two engines are identical except that engine A is two years old and engine B is new. If engine A does 15% less work than engine B under identical operating conditions, what is the ratio of the efficiencies of the two engines, eA/eB?

Accepted Answer

A) 0.10 
B) 0.15 
C) 0.85 
D) 0.90 
E) 1.0 
A) 0.10 
B) 0.15 
C) 0.85 
D) 0.90 
E) 1.0

Question 18

What are the SI units of the product of pressure and volume, PV?

Accepted Answer

A) newton 
B) kilogram · meter/second 
C) joule 
D) meter2 
E) newton · second 
A) newton 
B) kilogram · meter/second 
C) joule 
D) meter2 
E) newton · second

Question 19

During one stage of a reversible process, the temperature of an ideal gas remains constant as its volume is decreased. Which one of the following statements concerning this situation is true?

Accepted Answer

A) The process is adiabatic. 
B) The pressure of the gas decreases in this process. 
C) Heat flows out of the gas and into the surroundings. 
D) The gas does "positive" work on its surroundings. 
E) The average kinetic energy of the gas molecules increases. 
A) The process is adiabatic. 
B) The pressure of the gas decreases in this process. 
C) Heat flows out of the gas and into the surroundings. 
D) The gas does "positive" work on its surroundings. 
E) The average kinetic energy of the gas molecules increases.

Exam 15: Thermodynamics

Which one of the following statements is not a consequence of the second law of thermodynamics?

An engine is used to lift a 2700-kg truck to a height of 3.0 m at constant speed. In the lifting process, the engine received 4.18 × 105 J of heat from the fuel burned in its interior. What is the efficiency of the engine?

In an isothermal process, 1.59 moles of an ideal gas is compressed to one-fifth of its initial volume at 285 K. What quantity of heat is added to, or removed from, the system during this process?

In which one of these processes will there be no net change in the entropy of the system?

A block that slides on a rough surface slows down and eventually stops. The reverse process never occurs. That is, a block at rest never begins to move and accelerate on a rough surface without the action of an external agent. The second situation is forbidden because it would violate

Complete the following statement: The first law of thermodynamics states that

If one complete cycle of a reversible process is carried out on a sample of an ideal gas so that its final state is the same as its initial state, which one of the following quantities is the only one which can be non-zero?

A Carnot engine has a heat input of 3700 J and heat exhaust of 1400 J. What is the ratio of the Kelvin temperature of the hot reservoir to that of the cold reservoir, TH/TC?

Under which one of the following conditions would a Carnot heat engine be 100% efficient?

A heat pump is found to remove 2400 J of heat from the exterior of a house and deliver 3500 J of heat to the interior of the house. What is the coefficient of performance of the heat pump?

A heat engine operates between a hot reservoir at 1500 K and a cold reservoir at 500 K. During each cycle, 1.0 × 105 J of heat is removed from the hot reservoir and 5.0 × 104 J of work is performed. -What is the actual efficiency of this engine?

A heat engine operates between a hot reservoir at 1500 K and a cold reservoir at 500 K. During each cycle, 1.0 × 105 J of heat is removed from the hot reservoir and 5.0 × 104 J of work is performed. -Determine the Carnot efficiency of this engine.

Beneath the moveable piston in the drawing,2.25 moles of a monatomic ideal gas is enclosed at 314 K. The initial volume of the gas is 3.0 m3. The gas is compressed isothermally to a final volume of 1.0 m3. How much heat is removed from the gas during this process?

A fixed amount of ideal gas is compressed adiabatically. Which entry in the table below correctly indicates the sign of the work done, the change in the internal energy, and the heat exchanged with the environment? work done change in internal energy heat exchanged

An ideal gas is taken from state A to state B through process shown on the pressure-volume graph. How much heat is added to the gas in this process?

An ideal monatomic gas expands isothermally from state A to state B. The gas then cools at constant volume to state C. The gas is then compressed isobarically to D before it is heated until it returns to state A. -What is the pressure of the gas when it is in state B?

Two engines are identical except that engine A is two years old and engine B is new. If engine A does 15% less work than engine B under identical operating conditions, what is the ratio of the efficiencies of the two engines, eA/eB?

What are the SI units of the product of pressure and volume, PV?

During one stage of a reversible process, the temperature of an ideal gas remains constant as its volume is decreased. Which one of the following statements concerning this situation is true?

Introduction and Mathematical Concepts

Kinematics in One Dimension

Kinematics in Two Dimensions

Forces and Newtons Laws of Motion

Dynamics of Uniform Circular Motion

Work and Energy

Impulse and Momentum

Rotational Kinematics

Rotational Dynamics

Simple Harmonic Motion and Elasticity

Fluids

Temperature and Heat

The Transfer of Heat

The Ideal Gas Law and Kinetic Theory

Waves and Sound

The Principle of Linear Superposition and Interference Phenomena

Electric Forces and Electric Fields

Electric Potential Energy and the Electric Potential

Electric Circuits

Magnetic Forces and Magnetic Fields

Electromagnetic Induction

Alternating Current Circuits

Electromagnetic Waves

The Refl Ection of Light: Mirrors

The Refraction of Light: Lenses and Optical Instruments

Interference and the Wave Nature of Light

Special Relativity

Particles and Waves

The Nature of the Atom

Nuclear Physics and Radioactivity

Ionizing Radiation, Nuclear Energy, and Elementary Particles

Filters

An engine is used to lift a 2700-kg truck to a height of 3.0 m at constant speed. In the lifting process, the engine received 4.18 × 10⁵ J of heat from the fuel burned in its interior. What is the efficiency of the engine?

A Carnot engine has a heat input of 3700 J and heat exhaust of 1400 J. What is the ratio of the Kelvin temperature of the hot reservoir to that of the cold reservoir, T_H/T_C?

A heat engine operates between a hot reservoir at 1500 K and a cold reservoir at 500 K. During each cycle, 1.0 × 10⁵ J of heat is removed from the hot reservoir and 5.0 × 10⁴ J of work is performed. -What is the actual efficiency of this engine?

A heat engine operates between a hot reservoir at 1500 K and a cold reservoir at 500 K. During each cycle, 1.0 × 10⁵ J of heat is removed from the hot reservoir and 5.0 × 10⁴ J of work is performed. -Determine the Carnot efficiency of this engine.

Beneath the moveable piston in the drawing,2.25 moles of a monatomic ideal gas is enclosed at 314 K. The initial volume of the gas is 3.0 m³. The gas is compressed isothermally to a final volume of 1.0 m³. How much heat is removed from the gas during this process?

Two engines are identical except that engine A is two years old and engine B is new. If engine A does 15% less work than engine B under identical operating conditions, what is the ratio of the efficiencies of the two engines, e_A/e_B?