Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the (A) Cold reservoir approaches zero (B) Hot reservoir approaches infinity (C) Either (A) or (B) (D) Neither (A) nor (B)

Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the
(A) Cold reservoir approaches zero
(B) Hot reservoir approaches infinity
(C) Either (A) or (B)
(D) Neither (A) nor (B)
by

1 Answer

Answer :

C) Either (A) or (B)
by

Related questions

The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is (A) 100,000 kW (B) 160,000 kW (C) 200,000 kW (D) 320,000 kW

Description : The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is ... is (A) 100,000 kW (B) 160,000 kW (C) 200,000 kW (D) 320,000 kW

Last Answer : (D) 320,000 kW

Absolute zero temperature signifies the (A) Minimum temperature attainable (B) Temperature of the heat reservoir to which a Carnot engine rejects all the heat that is taken in (C) Temperature of the heat reservoir to which a Carnot engine rejects no heat (D) None of these

Description : Absolute zero temperature signifies the (A) Minimum temperature attainable (B) Temperature of the heat reservoir to which a Carnot engine rejects all the heat that is taken in (C) Temperature of the heat reservoir to which a Carnot engine rejects no heat (D) None of these

Last Answer : (C) Temperature of the heat reservoir to which a Carnot engine rejects no heat

Pick out the wrong statement. (A) Trouton's ratio of non-polar liquids is calculated using Kistyakowsky equation (B) Thermal efficiency of a Carnot engine is always less than 1 (C) An equation relating pressure, volume and temperature of a gas is called ideal gas equation (D) None of these

Description : Pick out the wrong statement. (A) Trouton's ratio of non-polar liquids is calculated using Kistyakowsky equation (B) Thermal efficiency of a Carnot engine is always less than 1 (C) An equation relating pressure, volume and temperature of a gas is called ideal gas equation (D) None of these

Last Answer : (C) An equation relating pressure, volume and temperature of a gas is called ideal gas equation

What is the highest efficiency of heat engine operating between the two thermal energy reservoirs at temperature limits?  A. Ericson efficiency  B. Otto efficiency  C. Carnot efficiency  D. Stirling efficiency

Description : What is the highest efficiency of heat engine operating between the two thermal energy reservoirs at temperature limits?  A. Ericson efficiency  B. Otto efficiency  C. Carnot efficiency  D. Stirling efficiency

Last Answer : Carnot efficiency

Which of the following has the least thermal efficiency? (A) Steam engine (B) Carnot engine (C) Diesel engine (D) Otto engine

Description : Which of the following has the least thermal efficiency? (A) Steam engine (B) Carnot engine (C) Diesel engine (D) Otto engine

Last Answer : A) Steam engine

As the temperature is lowered towards the absolute zero, the value of ∂(∆F)/∂T, then approaches (A) Unity (B) Zero (C) That of the heat of reaction (D) Infinity

Description : As the temperature is lowered towards the absolute zero, the value of ∂(∆F)/∂T, then approaches (A) Unity (B) Zero (C) That of the heat of reaction (D) Infinity

Last Answer : B) Zero

Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature. (A) Infinity (B) Minus infinity (C) Zero (D) None of these

Description : Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature. (A) Infinity (B) Minus infinity (C) Zero (D) None of these

Last Answer : (B) Minus infinity

As the temperature is lowered towards the absolute zero, the value of the quantity (∂∆F/∂T) approaches (A) Zero (B) Unity (C) Infinity (D) None of these

Description : As the temperature is lowered towards the absolute zero, the value of the quantity (∂∆F/∂T) approaches (A) Zero (B) Unity (C) Infinity (D) None of these

Last Answer : (A) Zero

Which of the following represents the perpetual motion of the first kind  (a) engine with 100% thermal efficiency  (b) a fully reversible engine  (c) transfer of heat energy from low temperature source to high temperature source  (d) a machine that continuously creates its own energy  (e) production of energy by temperature differential in sea water at different levels.

Description : Which of the following represents the perpetual motion of the first kind  (a) engine with 100% thermal efficiency  (b) a fully reversible engine  (c) transfer of heat energy from low ... its own energy  (e) production of energy by temperature differential in sea water at different levels.

Last Answer : Answer : d

In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is (A) Minimum (B) Maximum (C) Zero (D) Infinity

Description : In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is (A) Minimum (B) Maximum (C) Zero (D) Infinity

Last Answer : (C) Zero

Efficiency of a heat engine working on Carnot cycle between two temperature levels depends upon the (A) Two temperatures only (B) Pressure of working fluid (C) Mass of the working fluid (D) Mass and pressure both of the working fluid

Description : Efficiency of a heat engine working on Carnot cycle between two temperature levels depends upon the (A) Two temperatures only (B) Pressure of working fluid (C) Mass of the working fluid (D) Mass and pressure both of the working fluid

Last Answer : (A) Two temperatures only

Pick out the wrong statement. (A) The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively (B) Space time in a flow reactor is a measure of its capacity and is equal to the residence time when the density of reaction mixture is constant (C) Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty (D) In an ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction

Description : Pick out the wrong statement. (A) The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively (B) Space time in a flow reactor is a ... ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction

Last Answer : (C) Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty

Pick out the correct statement. (A) The available energy in an isolated system for all irreversible (real) processes decreases (B) The efficiency of a Carnot engine increases, if the sink temperature is decreased (C) The reversible work for compression in non-flow process under isothermal condition is the change in Helmholtz free energy (D) All (A), (B) and (C)

Description : Pick out the correct statement. (A) The available energy in an isolated system for all irreversible (real) processes decreases (B) The efficiency of a Carnot engine increases, if the sink temperature is decreased ... condition is the change in Helmholtz free energy (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

The thermal efficiency of a Watt’s Beam Engine is about? a) 50% b) 100% c) 5% d) 2%

Description : The thermal efficiency of a Watt’s Beam Engine is about? a) 50% b) 100% c) 5% d) 2%

Last Answer : d) 2%

According to first law of thermodynamics  (a) mass and energy are mutually convertible  (b) Carnot engine is most efficient  (c) heat and work are mutually convertible  (d) mass and light are mutually convertible  (e) heat flows from hot substance to cold substance.

Description : According to first law of thermodynamics  (a) mass and energy are mutually convertible  (b) Carnot engine is most efficient  (c) heat and work are mutually convertible  (d) mass and light are mutually convertible  (e) heat flows from hot substance to cold substance.

Last Answer : Answer : c

Carnot cycle efficiency depends upon  (a) properties of the medium/substance used  (b) condition of engine  (c) working condition  (d) temperature range of operation  (e) effectiveness of insulating material around the engine.

Description : Carnot cycle efficiency depends upon  (a) properties of the medium/substance used  (b) condition of engine  (c) working condition  (d) temperature range of operation  (e) effectiveness of insulating material around the engine.

Last Answer : Answer : d

The more effective way of increasing efficiency of Carnot engine is to  (a) increase higher temperature  (b) decrease higher temperature  (c) increase lower temperature  (d) decrease lower temperature  (e) keep lower temperature constant.

Description : The more effective way of increasing efficiency of Carnot engine is to  (a) increase higher temperature  (b) decrease higher temperature  (c) increase lower temperature  (d) decrease lower temperature  (e) keep lower temperature constant.

Last Answer : Answer : d

The most efficient cycle that can operate between two constant temperature reservoir is the _________.  a. Otto Cycle  b. Lazare Cycle  c. Isothermal Cycle  d. Carnot Cycle

Description : The most efficient cycle that can operate between two constant temperature reservoir is the _________.  a. Otto Cycle  b. Lazare Cycle  c. Isothermal Cycle  d. Carnot Cycle

Last Answer : Carnot Cycle

The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a refrigerator (COP)R and the co-efficient of performance as a heat pump (COP)HP are (A) (COP)R = (COP)HP = 0.6 (B) (COP)R = 2.5; (COP)HP = 1.5 (C) (COP)R = 1.5; (COP)HP = 2.5 (D) (COP)R = (COP)HP = 2.5

Description : The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a ... )R = 1.5; (COP)HP = 2.5 (D) (COP)R = (COP)HP = 2.5

Last Answer : (C) (COP)R = 1.5; (COP)HP = 2.5

The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1- T2)/T1. The co efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2is given by (A) T1/(T1-T2) (B) T2/(T1-T2) (C) T1/T2 (D) T2/R1

Description : The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1- T2)/T1. The co efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2is given by (A) T1/(T1-T2) (B) T2/(T1-T2) (C) T1/T2 (D) T2/R1

Last Answer : (A) T1/(T1-T2)

Efficiency of a Carnot engine working between temperatures T1 and T2(T1 < T) is (A) (T2- T1)/T2 (B) (T2- T1)/T1 (C) (T1- T2)/T2 (D) (T1- T2)/T1

Description : Efficiency of a Carnot engine working between temperatures T1 and T2(T1 < T) is (A) (T2- T1)/T2 (B) (T2- T1)/T1 (C) (T1- T2)/T2 (D) (T1- T2)/T1

Last Answer : (A) (T2- T1)/T2

The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2(when, T1 > T2) is given by (T1- T2)/T1. The co efficient of performance (CO.P.) of a Carnot heat pump operating between T1 and T2is given by (A) T1/(T1-T2) (B) T2/(T1-T2) (C) T1/T2 (D) T2/T1

Description : The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2(when, T1 > T2) is given by (T1- T2)/T1. The co efficient of performance (CO.P.) of a Carnot heat pump operating between T1 and T2is given by (A) T1/(T1-T2) (B) T2/(T1-T2) (C) T1/T2 (D) T2/T1

Last Answer : (B) T2/(T1-T2)

In a reservoir the average volume of sediment deposition is 0.15 million cubic per year. If the dead storage and total capacity of the reservoir are 8 million cubic metres and 36 million cubic metres respectively, (A) The reservoir will theoretically be silted in 240 years (B) The reservoir will start reducing after 60 years (C) Both (a) and (b) (D) Neither (a) nor (b)

Description : In a reservoir the average volume of sediment deposition is 0.15 million cubic per year. If the dead storage and total capacity of the reservoir are 8 million cubic metres and 36 million cubic metres respectively, (A) The ... reducing after 60 years (C) Both (a) and (b) (D) Neither (a) nor (b)

Last Answer : (C) Both (a) and (b)

A centrifugal pump is required to be primed before starting if it is located (A) At higher level than water level of reservoir (B) At lower level than water level of reservoir (C) Both (a) and (b) (D) Neither (a) nor (b)

Description : A centrifugal pump is required to be primed before starting if it is located  (A) At higher level than water level of reservoir  (B) At lower level than water level of reservoir  (C) Both (a) and (b)  (D) Neither (a) nor (b) 

Last Answer : (A) At higher level than water level of reservoir

In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

A cyclic engine exchanges heat with two reservoirs maintained at 100 and 300°C respectively. The maximum work (in J) that can be obtained from 1000 J of heat extracted from the hot reservoir is (A) 349 (B) 651 (C) 667 (D) 1000

Description : A cyclic engine exchanges heat with two reservoirs maintained at 100 and 300°C respectively. The maximum work (in J) that can be obtained from 1000 J of heat extracted from the hot reservoir is (A) 349 (B) 651 (C) 667 (D) 1000

Last Answer : (A) 349

Thermal conductivity of a conducting solid material depends upon its (A) Temperature (B) Porosity (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Thermal conductivity of a conducting solid material depends upon its (A) Temperature (B) Porosity (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Efficiency of a Carnot engine is given as 80%. If the- cycle direction be reversed, what will be the value of COP ofreversed Carnot cycle (a) 1.25 (b) 0.8 (c) 0.5 (d) 0.25

Description : Efficiency of a Carnot engine is given as 80%. If the- cycle direction be reversed, what will be the value of COP ofreversed Carnot cycle (a) 1.25 (b) 0.8 (c) 0.5 (d) 0.25

Last Answer : Ans: d

The efficiency of Carnot cycle is maximum for  (a) gas engine  (b) well lubricated engine  (c) petrol engine  (d) steam engine  (e) reversible engine.

Description : The efficiency of Carnot cycle is maximum for  (a) gas engine  (b) well lubricated engine  (c) petrol engine  (d) steam engine  (e) reversible engine.

Last Answer : Answer : e

The efficiency of a Carnot engine depends on  (a) working substance  (b) design of engine  (c) size of engine  (d) type of fuel fired  (e) temperatures of source and sink.

Description : The efficiency of a Carnot engine depends on  (a) working substance  (b) design of engine  (c) size of engine  (d) type of fuel fired  (e) temperatures of source and sink.

Last Answer : Answer : e

An actual engine is to be designed having same efficiency as the Carnot cycle. Such a proposition is  (a) feasible  (b) impossible  (c) possible  (d) possible, but with lot of sophistications  (e) desirable.

Description : An actual engine is to be designed having same efficiency as the Carnot cycle. Such a proposition is  (a) feasible  (b) impossible  (c) possible  (d) possible, but with lot of sophistications  (e) desirable.

Last Answer : Answer : d

Carnot cycle has maximum efficiency for  (a) reversible engine  (b) irreversible engine  (c) new engine  (d) petrol engine  (e) diesel engine.

Description : Carnot cycle has maximum efficiency for  (a) reversible engine  (b) irreversible engine  (c) new engine  (d) petrol engine  (e) diesel engine.

Last Answer : Answer : a

What states that thermal efficiencies of all reversible heat engines operating between the same two reservoirs are the same and that no heat engine is more efficient than a reversible one operating between the same two reservoirs?  A. Ericson principle  B. Carnot principle  C. Otto principle  D. Stirling principle

Description : What states that thermal efficiencies of all reversible heat engines operating between the same two reservoirs are the same and that no heat engine is more efficient than a reversible one operating between the ... A. Ericson principle  B. Carnot principle  C. Otto principle  D. Stirling principle

Last Answer : Carnot principle

For a thermodynamic process to be reversible, the temperature difference between hot body and working substance should be  (a) zero  (b) minimum  (d) maximum  (d) infinity  (e) there is no such criterion.

Description : For a thermodynamic process to be reversible, the temperature difference between hot body and working substance should be  (a) zero  (b) minimum  (d) maximum  (d) infinity  (e) there is no such criterion.

Last Answer : Answer : a

Consider the following statements: 1. Friction piles are also called floating piles 2. Minimum number of piles to qualify as a pile group is three. 3. The group efficiency of a pile group may be either less than 100% or more than 100%. Which of these statements are correct? (a) 1, 2 & 3 (b) 1 & 2 only (c) 2 & 3 only (d) 1 & 3 only

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Last Answer : (a) 1, 2 & 3

The thermal and electric pulp tests will, A. Give an accurate indications of the pulp status B. The patient’s response will be either pain or no pain C. The patient can differentiate between cold or hot stimuli

Description : The thermal and electric pulp tests will, A. Give an accurate indications of the pulp status B. The patient’s response will be either pain or no pain C. The patient can differentiate between cold or hot stimuli

Last Answer : A. Give an accurate indications of the pulp status

When cut-off ratio is __________ the efficiency of Diesel cycle approaches to Otto cycle efficiency.  A. zero  B. 1/5  C. 4/5  D. 1

Description : When cut-off ratio is __________ the efficiency of Diesel cycle approaches to Otto cycle efficiency.  A. zero  B. 1/5  C. 4/5  D. 1

Last Answer : Answer: A

The efficiency of Diesel cycle approaches to Otto cycle efficiency when  A. cut-off is increased  B. cut-off is decreased  C. cut-off is zero  D. cut-off is constant

Description : The efficiency of Diesel cycle approaches to Otto cycle efficiency when  A. cut-off is increased  B. cut-off is decreased  C. cut-off is zero  D. cut-off is constant

Last Answer : Answer: C

Which of the following are facts about a top-down software testing approach? I. Top-down testing typically requires the tester to build method stubs. II. Top-down testing typically requires the tester to build test drivers. (1) only I (2) Only II (3) Both I and II (4) Neither I nor II

Description : Which of the following are facts about a top-down software testing approach? I. Top-down testing typically requires the tester to build method stubs. II. Top-down testing typically requires the tester to build test drivers. (1) only I (2) Only II (3) Both I and II (4) Neither I nor II

Last Answer : (1) only I

Abstraction and encapsulation are fundamental principles that underlie the object oriented approach to software development. What can you say about the following two statements? I. Abstraction allows us to focus on what something does without considering the complexities of how it works. II. Encapsulation allows us to consider complex ideas while ignoring irrelevant detail that would confuse us. (1) Neither I nor II is correct. (2) Both I and II are correct. (3) Only II is correct. (4) Only I is correct.

Description : Abstraction and encapsulation are fundamental principles that underlie the object oriented approach to software development. What can you say about the following two statements? I. Abstraction allows us to focus on what something ... and II are correct. (3) Only II is correct. (4) Only I is correct.

Last Answer : (1) Neither I nor II is correct.

The term "approach" in a cooling tower refers to the difference in the temperature of the (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air (B) Hot water entering the tower and the wet bulb temperature of the surrounding air (C) Hot water entering and the cooled water leaving the cooling tower (D) None of these

Description : The term "approach" in a cooling tower refers to the difference in the temperature of the (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air (B ... (C) Hot water entering and the cooled water leaving the cooling tower (D) None of these

Last Answer : (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air

When the number of sides of a polygon tends to infinity, it approaches _______.

Description : When the number of sides of a polygon tends to infinity, it approaches _______.

Last Answer : When the number of sides of a polygon tends to infinity, it approaches _______.

If the overall efficiency and Murphree plate efficiency are equal, then both the equilibrium and operating lines are: (A) Straight (B) Parallel (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : If the overall efficiency and Murphree plate efficiency are equal, then both the equilibrium and operating lines are: (A) Straight (B) Parallel (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (A) Plug

The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (B) Perfectly mixed

The main feature of Carnot refrigeration cycle is that, it (A) Does not need the addition of external work for its functioning (B) Transfers heat from high temperature to low temperature (C) Accomplishes the reverse effect of the heat engine (D) None of these

Description : The main feature of Carnot refrigeration cycle is that, it (A) Does not need the addition of external work for its functioning (B) Transfers heat from high temperature to low temperature (C) Accomplishes the reverse effect of the heat engine (D) None of these

Last Answer : (C) Accomplishes the reverse effect of the heat engine

Is it possible to have a heat engine with 100% efficiency? If no why?

Description : Is it possible to have a heat engine with 100% efficiency? If no why?

Last Answer : No, we cannot have a heat engine that is 100% efficient. Whenever heat energy is converted into mechanical energy by a heat engine, a part of the heat energy is lost. Hence we cannot have 100% efficient.

A bolometer is (A) Used for the measurement of thermal radiation (B) An element which senses optical input and delivers thermal output (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : A bolometer is (A) Used for the measurement of thermal radiation (B) An element which senses optical input and delivers thermal output (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)