High School
SAT
ACT
University
MCAT
LSAT
DAT

Thermodynamics: Heat Engines

Related Topics

Wize University Physics Textbook (Master) > Thermodynamics

Heat Engines

3 Activities

Wize University Physics Textbook (Master) > Thermodynamics

Thermodynamic Cycles

3 Activities

checklist
Mark Yourself Question
  1. Grab a piece of paper and try this problem yourself.
  2. When you're done, check the "I have answered this question" box below.
  3. View the solution and report whether you got it right or wrong.
A diatomic gas undergoes some thermodynamical processes according to the following plot. Imagine the process from a to b could be changed in order to get different efficiency for the following cycle under the condition that the temperature of the gas cannot exceed the temperature at point a during the entire cycle. What is the work done by the gas from a to b in a process which makes the efficiency of the heat engine equal to the half of the efficiency of a Carnot engine which works in the same range of temperatures? (Assume we have 2 moles of the gas)

More Heat Engines Questions:
A Carnot engine has an efficiency of 33.0% It operates between constant reservoirs differing in temperature by 95oC.
What are the temperatures of the two reservoirs?
Entropy: Heat Engines
A cylinder contains Nitrogen gas (𝐢v = 20.8Jmol.K\frac{J}{mol.K} , 𝛾 = 1.4) at a pressure of 3 atm and a temperature of 250K. Its initial volume is 2.0 liters. The Nitrogen gas is next carried through the following processes:
a. It is heated in an isochoric process to a temperature of 375K
b. It is expanded at a constant temperature to a volume of 3.0 liters
Heat Engines: Otto Cycle
Otto Cycle is made of two isochoric processes at 𝑉0 and π‘Ÿπ‘‰0 for π‘Ÿ > 1 and two adiabatic processes which compress and extend the gas between these two volumes.
Plot PV curve of this cycle and find its efficiency in terms of only compression ratio, π‘Ÿ and 𝛾.
In a Stirling heat engine, a monatomic ideal gas at initial volume V1 and temperature T1, takes in heat at a constant volume until its temperature is T2, and then expands isothermally until its volume is V2. It gives out heat at a constant volume until its temperature is again T1 and then returns to its initial state by isothermal contraction. Calculate the efficiency and compare with a Carnot engine operating between the same two temperatures.
PV Curve: Heat Engines
In a Diesel cycle Vo volume of gas is expanded in an isobaric process to
𝛼𝑉o and then is expanded more to π‘Ÿπ‘‰o in an adiabatic process. The gas in then cooled down via an isochoric process and then is compressed back to its initial volume. Draw PV curve of this cycle and find the efficiency of this cycle only in terms of 𝛼, π‘Ÿ ,and 𝛾.
Entropy: Heat Engines
A cylinder contains a diatomic gas at a pressure of 3 atm and a temperature of 250K. Its initial volume is 4.0 liters. The gas is next carried through the following processes:
a. It is expanded isobarically to a temperature of 375K.
b. It is cooled down to 250K in an isochoric process.
Which one of the following statements best describes the operation of a heat engine?
For heat engine cycle is
clockwise
while for heat pump cycle is
counterclockwise
An engine is found to have an efficiency of 0.40. If it does 200 J of work per cycle, what are the corresponding quantities of heat absorbed and rejected?
More Thermodynamic Cycles Questions:
Thermodynamic Cycle (PV Diagram)
0.5 mole of a gas undergoes a cycle shown below. Find the heat has been added/removed from the gas during this cycle?
New Practice Question
An engineer wants to design! A thermodynamic path in order to increase the temperature of 1000 lit of a diatomic gas from 350K to 850K. He is considering two different options. The first method is to increase the temperature using a series of alternating adiabatic and isothermal processes so that during each adiabatic process the gas is heated up by 100K and then is expanded to its original volume through an isothermal process. The second method is to raise the temperature through a single isochoric process.
a) Draw P-V and T-S curves for both methods
b) In which method the heat added to the gas is less?
The internal energy of a system remains constant during
cyclic
process.
Heat engine
A reversible heat engine has a pV diagram shown on the graph. Determine the net heat transferred between the engine and environment in one cycle.