An ideal gas is heated at constant volume and then expanded isothermally. Show processes on P-V & T-S diagrams.

An ideal gas is heated at constant volume and then expanded isothermally. Show processes on P-V & T-S diagrams.
by

1 Answer

Answer :

image

Process 1-2 : Constant volume process

Process 2-3 : Constant temperature process (Isothermal process)

by

Related questions

If an ideal gas is isothermally expanded, what will its internal energy?

Description : If an ideal gas is isothermally expanded, what will its internal energy?

Last Answer : Remain the same

The air standard Otto cycle comprises a two constant pressure processes and two constant volume processes b two constant pressure and two constant entropy processes c. two constant volume processes and two constant entropy processes d. none of the above.

Description : The air standard Otto cycle comprises a two constant pressure processes and two constant volume processes b two constant pressure and two constant entropy processes c. two constant volume processes and two constant entropy processes d. none of the above.

Last Answer : ANSWER (c) two constant volume processes and two constant entropy processes

In reciprocating compressors, one should aim at compressing the air A. Adiabatically B. Isentropically C. Isothermally D. Polytropically

Description : In reciprocating compressors, one should aim at compressing the air A. Adiabatically B. Isentropically C. Isothermally D. Polytropically

Last Answer : ANSWER : C

A gas having a volume of100 ft³ at 27ºC is expanded to 120 ft³by heated at constant pressure to what temperature has it been heated to have this new volume?  a. 87°C  b. 85°C  c. 76°C  d. 97°C t2= T2–T1

Description : A gas having a volume of100 ft³ at 27ºC is expanded to 120 ft³by heated at constant pressure to what temperature has it been heated to have this new volume?  a. 87°C  b. 85°C  c. 76°C  d. 97°C t2= T2–T1

Last Answer : 87°C

Which is not constant for an ideal gas? (A) (∂P/∂V)T (B) (∂V/∂T)P (C) (∂P/∂V)V (D) All (A), (B) & (C)

Description : Which is not constant for an ideal gas? (A) (∂P/∂V)T (B) (∂V/∂T)P (C) (∂P/∂V)V (D) All (A), (B) & (C)

Last Answer : (A) (∂P/∂V)T

For perfect gas a. cp – cv = R b. cp + cv = R c. cp / cv = R d. cp X cv = R Where cp & cv are specific heats at constant pressure and volume.

Description : For perfect gas a. cp – cv = R b. cp + cv = R c. cp / cv = R d. cp X cv = R Where cp & cv are specific heats at constant pressure and volume.

Last Answer : ANSWER a. CP – CV = R

3.0 lbm of air are contained at 25 psia and 100 ˚F. Given that Rair = 53.35 ft-lbf/lbm- ˚F, what is the volume of the container?  A.10.7 ft^3  B.14.7 ft^3  C.15 ft^3  D.24.9 ft^3 Formula: use the ideal gas law pV = mRT T = (100 +460) ˚R V = mRT/p

Description : 3.0 lbm of air are contained at 25 psia and 100 ˚F. Given that Rair = 53.35 ft-lbf/lbm- ˚F, what is the volume of the container?  A.10.7 ft^3  B.14.7 ft^3  C.15 ft^3  D.24.9 ft^3 Formula: use the ideal gas law pV = mRT T = (100 +460) ˚R V = mRT/p

Last Answer : 24.9 ft^3

If air is at pressure, p, of 3200 lbf/ft2 , and at a temperature, T, of 800 ˚R, what is the specific volume, v? (R=5303 ft-lbf/lbm-˚R, and air can be modeled as an ideal gas.)  A.9.8 ft^3/lbm  B.11.2 ft^3/lbm  C.13.33 ft^3/lbm  D.14.2 ft^3/lbm Formula: pv = RT v = RT / p

Description : If air is at pressure, p, of 3200 lbf/ft2 , and at a temperature, T, of 800 ˚R, what is the specific volume, v? (R=5303 ft-lbf/lbm-˚R, and air can be modeled as an ideal gas.)  A.9.8 ft^3/lbm  B.11.2 ft^3/lbm  C.13.33 ft^3/lbm  D.14.2 ft^3/lbm Formula: pv = RT v = RT / p

Last Answer : 13.33 ft^3/lbm

On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line (∂P/∂V)T are related as (where, y = Cp/Cv) (A) (∂P/∂V)S = (∂P/∂V)T (B) (∂P/∂V)S = [(∂P/∂V)T]Y (C) (∂P/∂V)S = y(∂P/∂V)T (D) (∂P/∂V)S = 1/y(∂P/∂V)T

Description : On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line ... Y (C) (∂P/∂V)S = y(∂P/∂V)T (D) (∂P/∂V)S = 1/y(∂P/∂V)T

Last Answer : (C) (∂P/∂V)S = y(∂P/∂V)T

If a gas is heated against a pressure, keeping the volume constant, then work done will be equal to  (a) + v  (b) – ve  (c) zero  (d) pressure x volume  (e) any where between zero and infinity.

Description : If a gas is heated against a pressure, keeping the volume constant, then work done will be equal to  (a) + v  (b) – ve  (c) zero  (d) pressure x volume  (e) any where between zero and infinity.

Last Answer : Answer : c

What ideal gas is stored in a container at constant volume. If the temperature (T) were increased to 3T what would be the change in pressure (P)?

Description : What ideal gas is stored in a container at constant volume. If the temperature (T) were increased to 3T what would be the change in pressure (P)?

Last Answer : Feel Free to Answer

Represent constant volume process on PV & TS diagram for steam.

Description : Represent constant volume process on PV & TS diagram for steam.

Last Answer : Represent constant volume process on PV & TS diagram for steam.

An ideal gas at 45psig and 80ºF is heated in the close container to 130ºF. What is the final pressure?  a. 65.10 psi  b. 65.11 psi  c. 65.23 psi  d. 61.16 psi P1V1/T1= P2V2/T2;V = Constant

Description : An ideal gas at 45psig and 80ºF is heated in the close container to 130ºF. What is the final pressure?  a. 65.10 psi  b. 65.11 psi  c. 65.23 psi  d. 61.16 psi P1V1/T1= P2V2/T2;V = Constant

Last Answer : 65.23 psi

Represent generation of steam on H-S diagram. Show constant dryness fraction lines, constant temperature lines, saturated line and superheated region on the same.

Description : Represent generation of steam on H-S diagram. Show constant dryness fraction lines, constant temperature lines, saturated line and superheated region on the same.

Last Answer : Represent generation of steam on H-S diagram. Show constant dryness fraction lines, constant temperature lines, saturated line and superheated region on the same.

An ideal gas is compresses isothermally. The enthalpy change is  a. Always negative  b. Always positive  c. zero  d. undefined

Description : An ideal gas is compresses isothermally. The enthalpy change is  a. Always negative  b. Always positive  c. zero  d. undefined

Last Answer : zero

For a perfect gas, according to Boyle’s law (where p = Absolute pressure, v = Volume, and T = Absolute temperature)  A. p v = constant, if T is kept constant  B. v/T = constant, if p is kept constant  C. p/T = constant, if v is kept constant  D. T/p = constant, if v is kept constant

Description : For a perfect gas, according to Boyle’s law (where p = Absolute pressure, v = Volume, and T = Absolute temperature)  A. p v = constant, if T is kept constant  B. v/T = constant, if p is kept constant  C. p/T = constant, if v is kept constant  D. T/p = constant, if v is kept constant

Last Answer : Answer: A

A change in state involving a decrease in entropy can be spontaneous, only if (A) It is exothermic (B) It is isenthalpic (C) It takes place isothermally (D) It takes place at constant volume

Description : A change in state involving a decrease in entropy can be spontaneous, only if (A) It is exothermic (B) It is isenthalpic (C) It takes place isothermally (D) It takes place at constant volume

Last Answer : (A) It is exothermic

Air standard cycle uses ____ as a working medium. a. Perfect gas b. Real gas c. Ideal gas d. Natural gas

Description : Air standard cycle uses ____ as a working medium. a. Perfect gas b. Real gas c. Ideal gas d. Natural gas

Last Answer : ANSWER a. Perfect gas

In which of the following cycle heat is added at constant volume? a. Otto cycle b. Diesel cycle c. Dual cycle d. Carnot cycle

Description : In which of the following cycle heat is added at constant volume? a. Otto cycle b. Diesel cycle c. Dual cycle d. Carnot cycle

Last Answer : Answer a. Otto cycle

Gas is enclosed in a cylinder with a weighted piston as the stop boundary. The gas is heated and expands from a volume of 0.04 m^3 to 0.10 m^3 at a constant pressure of 200kPa.Calculate the work done by the system.  A. 8 kJ  B. 10 kJ  C.12 kJ  D.14 kJ Formula: W = p(V2-V1)

Description : Gas is enclosed in a cylinder with a weighted piston as the stop boundary. The gas is heated and expands from a volume of 0.04 m^3 to 0.10 m^3 at a constant pressure of 200kPa.Calculate the work done by the system.  A. 8 kJ  B. 10 kJ  C.12 kJ  D.14 kJ Formula: W = p(V2-V1)

Last Answer : 12 kJ

An engine indicator is used to determine the following A. Speed B. Temperature C. M.E.P D. Volume of cylinder

Description : An engine indicator is used to determine the following A. Speed B. Temperature C. M.E.P D. Volume of cylinder

Last Answer : ANSWER : C

An ideal air standard Otto cycle has a compression ratio of 8.5. If the ratio of the specific heats is 1.4, then what is thermal efficiency (in percentage) of the Otto cycle? a. 57.5% b. 45.7% c. 52.5% d. 95%

Description : An ideal air standard Otto cycle has a compression ratio of 8.5. If the ratio of the specific heats is 1.4, then what is thermal efficiency (in percentage) of the Otto cycle? a. 57.5% b. 45.7% c. 52.5% d. 95%

Last Answer : ANSWER a. 57.5%

Draw dual cycle on P V and T S diagram and write the processes involved in it.

Description : Draw dual cycle on P V and T S diagram and write the processes involved in it. 

Last Answer : 1-2 Isentropic compression of air  2-3 the combustion of fuel at constant volume.  3-4 the combustion of fuel at constant pressure  4-5 Isentropic expansion during which work is done by the system.  5-1 Heat rejection at constant volume. 

The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will (a) increase (b) decrease (c) remain unaffected (d) may increase or decrease depending on the type of refrigerant used

Description : The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will (a) increase (b) decrease (c) remain unaffected (d) may increase or decrease depending on the type of refrigerant used

Last Answer : Ans: a

If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressorrequired will be (a) same (b) more (c) less (d) more/less depending on rating

Description : If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressorrequired will be (a) same (b) more (c) less (d) more/less depending on rating

Last Answer : Ans: b

The internal energy of a gas obeying P (V - b) RT (where, b is a positive constant and has a constant Cv ), depends upon its (A) Pressure (B) Volume (C) Temperature (D) All (A), (B) & (C)

Description : The internal energy of a gas obeying P (V - b) RT (where, b is a positive constant and has a constant Cv ), depends upon its (A) Pressure (B) Volume (C) Temperature (D) All (A), (B) & (C)

Last Answer : (C) Temperature

Vertical lines on pressure-enthalpy chart show constant (a) pressure lines (b) temperature lines (c) total heat lines (d) entropy lines

Description : Vertical lines on pressure-enthalpy chart show constant (a) pressure lines (b) temperature lines (c) total heat lines (d) entropy lines

Last Answer : Ans: c

Short horizontal lines on pressure-enthalpy chart show (a) constant pressure lines (b) constant temperature lines (c) constant total heat lines (d) constant entropy lines

Description : Short horizontal lines on pressure-enthalpy chart show (a) constant pressure lines (b) constant temperature lines (c) constant total heat lines (d) constant entropy lines

Last Answer : Ans: a

What is the perfect condition for dehumidification of air? A. air is heated above its dew point temperature B. air is cooled up to its dew point temperature C. air is heated below its dew point temperature D. air is cooled below its dew point temperature

Description : What is the perfect condition for dehumidification of air? A. air is heated above its dew point temperature B. air is cooled up to its dew point temperature C. air is heated below its dew point temperature D. air is cooled below its dew point temperature

Last Answer : ANSWER : D

When the humidity ratio of air increases the air is said to be A. dehumidified B. humidified C. heated D. cooled

Description : When the humidity ratio of air increases the air is said to be A. dehumidified B. humidified C. heated D. cooled

Last Answer : ANSWER : B

The power required to drive a turbo compressor for a given pressure ratio decreases when A. Air is heated at entry B. Air is cooled at entry C. Air is cooled at exit D. Air is heated at exit

Description : The power required to drive a turbo compressor for a given pressure ratio decreases when A. Air is heated at entry B. Air is cooled at entry C. Air is cooled at exit D. Air is heated at exit

Last Answer : ANSWER : B

Which of the following is the Ideal gas law (equation)?  A. V/T = K  B. V= k*(1/P)  C. P1/T1 = P2/T2  D. PV = nRT

Description : Which of the following is the Ideal gas law (equation)?  A. V/T = K  B. V= k*(1/P)  C. P1/T1 = P2/T2  D. PV = nRT

Last Answer : PV = nRT

Differentiate between isothermal and isentropic processes

Description : Differentiate between isothermal and isentropic processes

Last Answer : Isothermal Vs Isentropic

The _____________ sensor, monitors mass or volume of air flowing into the intake manifold for adjusting the quantity of fuel. a) engine temperature b) exhaust gas c) air flow d) air inlet temperature

Description : The _____________ sensor, monitors mass or volume of air flowing into the intake manifold for adjusting the quantity of fuel. a) engine temperature b) exhaust gas c) air flow d) air inlet temperature

Last Answer : Answer: c Explanation: The air flow sensor, monitors mass or volume of air flowing into the intake manifold for adjusting the quantity of fuel while exhaust gas senor senses the amount of oxygen in the engine exhaust and calculates air-fuel ratio.

The heating value per unit volume of hydrogen gas is less than ______________ that of air. a) 1/12th b) 1/10th c) 2/3rd d) 1/3rd

Description : The heating value per unit volume of hydrogen gas is less than ______________ that of air. a) 1/12th b) 1/10th c) 2/3rd d) 1/3rd

Last Answer : Answer: d Explanation: None

A gas engine has a volume of 300 cc and clearance volume of 25 cc. Its volumetric efficiency is 0.8 and mech efficiency is 0.9. What is the volume of the mixture taken in per stroke? (a) 248 cc (b) 252 cc (c) 264 cc (d) 286 cc

Description : A gas engine has a volume of 300 cc and clearance volume of 25 cc. Its volumetric efficiency is 0.8 and mech efficiency is 0.9. What is the volume of the mixture taken in per stroke? (a) 248 cc (b) 252 cc (c) 264 cc (d) 286 cc

Last Answer : Ans : c

The compressibility factor, x, is used for predicting the behavior of nonideal gases. How is the compressibility ty factor defined relative to an ideal gas? (subscript “c”refers to critical value)  A. z = P / Pc  B. z = pV/ RT  C. z = T /Tc  D. z = RT / pV Hint: for an real gases the compressibility factor, x, is an dimensionless constant given by pV=zRT. Therefore z = pV / RT

Description : The compressibility factor, x, is used for predicting the behavior of nonideal gases. How is the compressibility ty factor defined relative to an ideal gas? (subscript c refers to critical value)  A. ... compressibility factor, x, is an dimensionless constant given by pV=zRT. Therefore z = pV / RT

Last Answer : z = pV/ RT

Consider a system with seven processes A through G and six resources R through W. Resource ownership is as follows: process A holds R and wants T process B holds nothing but wants T process C holds nothing but wants S process D holds U and wants S & T process E holds T and wants V process F holds W and wants S process G holds V and wants U Is the system deadlocked ? If yes, ............. processes are deadlocked. (A) No (B) Yes, A, B, C (C) Yes, D, E, G (D) Yes, A, B, F

Description : Consider a system with seven processes A through G and six resources R through W. Resource ownership is as follows: process A holds R and wants T process B holds nothing but wants T process C holds nothing but wants S process D holds U ... No (B) Yes, A, B, C (C) Yes, D, E, G (D) Yes, A, B, F

Last Answer : (C) Yes, D, E, G

With suction pressure being atmospheric, increase in delivery pressure with fixed clearance volume A. increase volumetric efficiency B. decrease volumetric efficiency C. does not change volumetric efficiency D. First increase volumetric efficiency and then decrease it

Description : With suction pressure being atmospheric, increase in delivery pressure with fixed clearance volume A. increase volumetric efficiency B. decrease volumetric efficiency C. does not change volumetric efficiency D. First increase volumetric efficiency and then decrease it

Last Answer : ANSWER : B

An engine working on air standard Otto cycle has a cylinder diameter of 10 cm and stroke length of 15 cm. The ratio of specific heats for air is 1.4. If the clearance volume is 196.3 cc and the heat supplied per kg of air per cycle is 1800 kJ/kg, then work output per cycle per kg of air is a. 879.1 kJ/ b. 890.2 kJ c. 895.3 kJ d. 973.5 kJ

Description : An engine working on air standard Otto cycle has a cylinder diameter of 10 cm and stroke length of 15 cm. The ratio of specific heats for air is 1.4. If the clearance volume is 196.3 cc and the heat supplied per kg of air per ... kg of air is a. 879.1 kJ/ b. 890.2 kJ c. 895.3 kJ d. 973.5 kJ

Last Answer : ANSWER d. 973.5 kJ

The gas used in a refrigerator is - (1) cooled down on flowing (2) heated up on flowing (3) cooled down when compressed (4) cooled down when expanded

Description : The gas used in a refrigerator is - (1) cooled down on flowing (2) heated up on flowing (3) cooled down when compressed (4) cooled down when expanded

Last Answer : (4) cooled down when expanded Explanation: Common refrigerants used in various applications are ammonia, sulfur dioxide, and non-halogenated hydrocarbons such as propane. Compressing these gasses into liquids they are made to give up their heat.

The characteristic equation of gases pv = mRT holds good for (a) mono atomic gases (b) diatomic gases (c)real gases (d) ideal gases

Description : The characteristic equation of gases pv = mRT holds good for (a) mono atomic gases (b) diatomic gases (c)real gases (d) ideal gases

Last Answer : Ans: c

The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is A. Less B. More C. Same D. Unpredictable

Description : The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is A. Less B. More C. Same D. Unpredictable

Last Answer : ANSWER : B

In a two stage reciprocating air compressor with a suction pressure of 2 bar and delivery pressure of 8 bar the ideal intercooler pressure will be A. 10 bar B. 6 bar C. 4 bar D. 3 bar

Description : In a two stage reciprocating air compressor with a suction pressure of 2 bar and delivery pressure of 8 bar the ideal intercooler pressure will be A. 10 bar B. 6 bar C. 4 bar D. 3 bar

Last Answer : ANSWER : C

A gas is compressed from 1 bar and 30°C to 5 bars and 30°C. Identify process and show on PV diagram.

Description : A gas is compressed from 1 bar and 30°C to 5 bars and 30°C. Identify process and show on PV diagram.

Last Answer : Gas is compressed from (1) 1 bar 30 0C to (2) 5 bar 30 0C Temp is constant. Hence process is isothermal. P x V = Constant

The volume (V) of a mass of gas varies directly as its absulute temperature (T) and iversely as the pressure (P) applied to it. The gas occupies a vol

Description : The volume (V) of a mass of gas varies directly as its absulute temperature (T) and iversely as the pressure (P) applied to it. The gas occupies a vol

Last Answer : The volume (V) of a mass of gas varies directly as its absulute temperature (T) and iversely as ... and pressure are 250 ml and 320 Pa respectively?

The volume (V) of a mass of gas varies directly as its absolute temperature (T) and inversely as the pressure (P) applied to it. The gas occupies a vo

Description : The volume (V) of a mass of gas varies directly as its absolute temperature (T) and inversely as the pressure (P) applied to it. The gas occupies a vo

Last Answer : The volume (V) of a mass of gas varies directly as its absolute temperature (T) and inversely as ... and pressure are 200 ml and 250 Pa respectively?

When vapour is compressed isothermally the ____________ changes. A] Volume. B] Pressure C] Temperature D] None of the mentioned

Description : When vapour is compressed isothermally the ____________ changes. A] Volume. B] Pressure C] Temperature D] None of the mentioned

Last Answer : A] Volume.

Boyle's law states that A. pressure of a gas is inversely proportional to its volume i.e. P × V = constant B. pressure of a gas is directly proportional to its volume i.e. P⁄V = constant C. pressure of a gas is inversely proportional to the square of its volume i.e. P × V² = constant D. pressure of a gas is directly proportional to the square of its volume i.e. P ⁄ V² = constant

Description : Boyle's law states that A. pressure of a gas is inversely proportional to its volume i.e. P V = constant B. pressure of a gas is directly proportional to its volume i.e. P⁄V = constant C. ... of a gas is directly proportional to the square of its volume i.e. P ⁄ V² = constant

Last Answer : pressure of a gas is inversely proportional to its volume i.e. P × V = constant