Question 1

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 2

A quantity of carbon monoxide gas is slowly compressed adiabatically in an insulated container to one-half of its initial volume.The ratio of the specific heat capacities at constant pressure and constant volume,cP/cV ,for carbon dioxide is approximately 1.3.Determine the final pressure of the gas if the initial pressure is 2.0 × 10⁵ Pa.

Accepted Answer

A) 2.0 × 10⁵ Pa 
B) 2.6 × 10⁵ Pa 
C) 3.7 × 10⁵ Pa 
D) 4.9 × 10⁵ Pa 
E) 5.2 × 10⁵ Pa 
A) 2.0 × 10⁵ Pa 
B) 2.6 × 10⁵ Pa 
C) 3.7 × 10⁵ Pa 
D) 4.9 × 10⁵ Pa 
E) 5.2 × 10⁵ Pa

Question 3

Two moles of a confined ideal monatomic gas begin at state A on the pressure-volume graph and follow the path shown to state D.If the temperature of the gas at A is 54 K,what is the temperature of the gas at D?

Accepted Answer

A) 32 K 
B) 46 K 
C) 54 K 
D) 60 K 
E) 78 K 
A) 32 K 
B) 46 K 
C) 54 K 
D) 60 K 
E) 78 K

Question 4

An ideal monatomic gas originally in state A is taken reversibly to state B along the straight-line path shown in the pressure-volume graph.
  
-What is the change in the internal energy,in calories,of the gas for this process?

Accepted Answer

A) zero calories 
B) +12 cal 
C) -110 cal 
D) +110 cal 
E) +122 cal 
A) zero calories 
B) +12 cal 
C) -110 cal 
D) +110 cal 
E) +122 cal

Question 5

A gasoline engine with an efficiency of 0.40 generates 1800 W of power.If a liter of gasoline has an energy content of 3.7 × 10⁷ J,how many liters of gasoline does the engine consume each hour?

Accepted Answer

A) 0.36 
B) 0.44 
C) 1.4 
D) 2.8 
E) 6.9 
A) 0.36 
B) 0.44 
C) 1.4 
D) 2.8 
E) 6.9

Question 6

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.
-If the coefficient of performance for a refrigerator is 5.0 and 72 J of work are done on the system,how much heat is rejected to the room?

Accepted Answer

A) 390 J 
B) 430 J 
C) 360 J 
D) 310 J 
E) 530 J 
A) 390 J 
B) 430 J 
C) 360 J 
D) 310 J 
E) 530 J

Question 7

What change in temperature occurs when 1600 J of heat are removed from 3.0 moles of monatomic gas under constant pressure?

Accepted Answer

A) -8.1 K 
B) -12 K 
C) -15 K 
D) -26 K 
E) -38 K 
A) -8.1 K 
B) -12 K 
C) -15 K 
D) -26 K 
E) -38 K

Question 8

An ideal monatomic gas expands isobarically from state A to state B.It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A.
  
-How much work is done on the gas in going from B to C?

Accepted Answer

A) 2.5 × 10⁶ J 
B) 5.5 × 10⁶ J 
C) 4.5 × 10⁶ J 
D) 6.5 × 10⁶ J 
E) 8.0 × 10⁶ J 
A) 2.5 × 10⁶ J 
B) 5.5 × 10⁶ J 
C) 4.5 × 10⁶ J 
D) 6.5 × 10⁶ J 
E) 8.0 × 10⁶ J

Question 9

A container holding 1.2 kg of water at 20.0 °C is placed in a freezer that is kept at -20.0 °C.The water freezes and comes into thermal equilibrium with the interior of the freezer.
-What is the minimum amount of electrical energy required by the refrigerator to carry out this process if it operates between reservoirs at temperatures of 20.0 °C and -20.0 °C?

Accepted Answer

A) 63 000 J 
B) 77 000 J 
C) 87 000 J 
D) 348 000 J 
E) 549 000 J 
A) 63 000 J 
B) 77 000 J 
C) 87 000 J 
D) 348 000 J 
E) 549 000 J

Question 10

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 11

In a reversible heat engine,one mole of an ideal gas is carried through a circular cycle beginning and ending at point A as shown in the figure.Which one of the following statements concerning this system is false?

Accepted Answer

A) The entropy must increase in one cycle. 
B) The heat added in one cycle must be 314 J. 
C) The work done in completing one cycle is 314 J. 
D) The change in internal energy for one cycle is zero joules. 
E) The internal energy for this system is dependent on its state. 
A) The entropy must increase in one cycle. 
B) The heat added in one cycle must be 314 J. 
C) The work done in completing one cycle is 314 J. 
D) The change in internal energy for one cycle is zero joules. 
E) The internal energy for this system is dependent on its state.

Question 12

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 13

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 14

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.

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 15

A heat engine operates in a Carnot cycle between reservoirs of temperatures 1000 K and 400 K.It is found to discharge 20 J of heat per cycle to the cold reservoir.What is the work output per cycle?

Accepted Answer

A) 10 J 
B) 20 J 
C) 30 J 
D) 40 J 
E) 50 J 
A) 10 J 
B) 20 J 
C) 30 J 
D) 40 J 
E) 50 J

Question 16

The ratio of the molar specific heat capacity at constant pressure to that at constant volume,g,for diatomic hydrogen gas is 7/5.In an adiabatic compression,the gas,originally at atmospheric pressure,is compressed from an original volume of 0.30 m³ to 0.10 m³.What is the final pressure of the gas?

Accepted Answer

A) 2.0 × 10⁵ Pa 
B) 2.7 × 10⁵ Pa 
C) 3.1 × 10⁵ Pa 
D) 3.8 × 10⁵ Pa 
E) 4.7 × 10⁵ Pa 
A) 2.0 × 10⁵ Pa 
B) 2.7 × 10⁵ Pa 
C) 3.1 × 10⁵ Pa 
D) 3.8 × 10⁵ Pa 
E) 4.7 × 10⁵ Pa

Question 17

An ideal monatomic gas expands isobarically from state A to state B.It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A.
  
-What is the temperature of the gas when it is in state B?

Accepted Answer

A) 437 K 
B) 573 K 
C) 927 K 
D) 1200 K 
E) 1473 K 
A) 437 K 
B) 573 K 
C) 927 K 
D) 1200 K 
E) 1473 K

Question 18

Two moles of an ideal gas have an initial Kelvin temperature Tᵢ and absolute pressure Pᵢ.The gas undergoes a reversible isothermal compression from an initial volume Vᵢ to a final volume 0.5Vᵢ.
-How much heat is exchanged with the environment? If heat is exchanged,is it absorbed or released?

Accepted Answer

A) PᵢVᵢ (ln 2),released 
B) PᵢVᵢ (ln 2),absorbed 
C) (0.5)PᵢVᵢ,released 
D) (0.5)PᵢVᵢ,absorbed 
E) zero 
A) PᵢVᵢ (ln 2),released 
B) PᵢVᵢ (ln 2),absorbed 
C) (0.5)PᵢVᵢ,released 
D) (0.5)PᵢVᵢ,absorbed 
E) zero

Question 19

Which of the following samples exhibits the highest degree of entropy?

Accepted Answer

A) a diamond crystal 
B) ammonia vapor 
C) a block of graphite 
D) a block of paraffin 
E) liquid oxygen 
A) a diamond crystal 
B) ammonia vapor 
C) a block of graphite 
D) a block of paraffin 
E) liquid oxygen

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?

Two moles of a confined ideal monatomic gas begin at state A on the pressure-volume graph and follow the path shown to state D.If the temperature of the gas at A is 54 K,what is the temperature of the gas at D?

An ideal monatomic gas originally in state A is taken reversibly to state B along the straight-line path shown in the pressure-volume graph. -What is the change in the internal energy,in calories,of the gas for this process?

A gasoline engine with an efficiency of 0.40 generates 1800 W of power.If a liter of gasoline has an energy content of 3.7 × 10⁷ J,how many liters of gasoline does the engine consume each hour?

What change in temperature occurs when 1600 J of heat are removed from 3.0 moles of monatomic gas under constant pressure?

An ideal monatomic gas expands isobarically from state A to state B.It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A. -How much work is done on the gas in going from B to C?

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

In a reversible heat engine,one mole of an ideal gas is carried through a circular cycle beginning and ending at point A as shown in the figure.Which one of the following statements concerning this system is false?

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?

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 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.

A heat engine operates in a Carnot cycle between reservoirs of temperatures 1000 K and 400 K.It is found to discharge 20 J of heat per cycle to the cold reservoir.What is the work output per cycle?

The ratio of the molar specific heat capacity at constant pressure to that at constant volume,g,for diatomic hydrogen gas is 7/5.In an adiabatic compression,the gas,originally at atmospheric pressure,is compressed from an original volume of 0.30 m³ to 0.10 m³.What is the final pressure of the gas?

An ideal monatomic gas expands isobarically from state A to state B.It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A. -What is the temperature of the gas when it is in state B?

Two moles of an ideal gas have an initial Kelvin temperature Tᵢ and absolute pressure Pᵢ.The gas undergoes a reversible isothermal compression from an initial volume Vᵢ to a final volume 0.5Vᵢ. -How much heat is exchanged with the environment? If heat is exchanged,is it absorbed or released?

Which of the following samples exhibits the highest degree of entropy?

Fluids

The Transfer of Heat

The Ideal Gas Law and Kinetic Theory

The Principle of Linear Superposition and Interference Phenomena

Electric Circuits

Electromagnetic Induction

The Refl Ection of Light: Mirrors

The Refraction of Light: Lenses and Optical Instruments

Particles and Waves

Filters

Exam 15: Thermodynamics

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?

Two moles of a confined ideal monatomic gas begin at state A on the pressure-volume graph and follow the path shown to state D.If the temperature of the gas at A is 54 K,what is the temperature of the gas at D?

An ideal monatomic gas originally in state A is taken reversibly to state B along the straight-line path shown in the pressure-volume graph. -What is the change in the internal energy,in calories,of the gas for this process?

A gasoline engine with an efficiency of 0.40 generates 1800 W of power.If a liter of gasoline has an energy content of 3.7 × 10⁷ J,how many liters of gasoline does the engine consume each hour?

What change in temperature occurs when 1600 J of heat are removed from 3.0 moles of monatomic gas under constant pressure?

An ideal monatomic gas expands isobarically from state A to state B.It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A. -How much work is done on the gas in going from B to C?

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

In a reversible heat engine,one mole of an ideal gas is carried through a circular cycle beginning and ending at point A as shown in the figure.Which one of the following statements concerning this system is false?

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?

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 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.

A heat engine operates in a Carnot cycle between reservoirs of temperatures 1000 K and 400 K.It is found to discharge 20 J of heat per cycle to the cold reservoir.What is the work output per cycle?

An ideal monatomic gas expands isobarically from state A to state B.It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A. -What is the temperature of the gas when it is in state B?

Which of the following samples exhibits the highest degree of entropy?

Fluids

The Transfer of Heat

The Ideal Gas Law and Kinetic Theory

The Principle of Linear Superposition and Interference Phenomena

Electric Circuits

Electromagnetic Induction

The Refl Ection of Light: Mirrors

The Refraction of Light: Lenses and Optical Instruments

Particles and Waves

Filters

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?