Define heat engine efficiency. ?

Define heat engine efficiency. ?
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Answer :

The ratio of the amount of heat energy converted to work by a heat engine and the amount of heat energy absorbed by the engine is called the efficiency of that heat engine.
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Description : What is the ideal efficiency of a reversible heat engine cyclically operating between a source temperature of 600 degrees Kelvin and a sink temperature of 150 degrees Kelvin?

Last Answer : ANSWER: 75 PERCENT

Define efficiency of a heat engine.

Description : Define efficiency of a heat engine.

Last Answer : The efficiency of a heat engine is defined as the ratio of the actual work done to the heat energy consumed. It is expressed as percentage.

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A diesel engine is usually more efficient than a spark ignition engine because a. Diesel being a heavier hydrocarbon, release more heat per kg than gasoline b. The air standard efficiency of diesel cycle is higher than the Otto cycle, at a fixed compression ratio c. The compression ratio of a diesel engine is higher than that of an Spark ignition engine d.Self ignition temperature of diesel is higher than that of gasoline.

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Last Answer : ANSWER c. The compression ratio of a diesel engine is higher than that of an S.I engine

For an engine operating on air standard Otto cycle, the clearance volume is 10% of the swept volume. The specific heat ratio of air is 1.4. The air standard cycle efficiency is a. 38.3 % b. 39.8 % c. 60.2 % d. 61.7 %

Description : For an engine operating on air standard Otto cycle, the clearance volume is 10% of the swept volume. The specific heat ratio of air is 1.4. The air standard cycle efficiency is a. 38.3 % b. 39.8 % c. 60.2 % d. 61.7 %

Last Answer : ANSWER d. 61.7%

How the efficiency of the SI engine is affected by the specific heat ratio (γ) of the working fluid? a. the efficiency of the engine increases with increase in specific heat ratio (γ) of the working fluid b. the efficiency of the engine decreases with increase in specific heat ratio (γ) of the working fluid c. the efficiency of the engine does not affected by change in specific heat ratio (γ) of the working fluid d. none of the above

Description : How the efficiency of the SI engine is affected by the specific heat ratio (γ) of the working fluid? a. the efficiency of the engine increases with increase in specific heat ratio (γ) of the working ... not affected by change in specific heat ratio (γ) of the working fluid d. none of the above

Last Answer : ANSWER a. the efficiency of the engine increases with increase in specific heat ratio (γ) of the working fluid

If work done by an engine is equal to the heat supplied, then its efficiency is

Description : If work done by an engine is equal to the heat supplied, then its efficiency is

Last Answer : 100%.

The formula to calculate the efficiency of a heat engine is

Description : The formula to calculate the efficiency of a heat engine is

Last Answer : W x 100

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.

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

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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)

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

Pick out the correct statement. (A) Compression ratio of an Otto engine is comparatively higher than a diesel engine (B) Efficiency of an Otto engine is higher than that of a diesel engine for the same compression ratio (C) Otto engine efficiency decreases with the rise in compression ratio, due to decrease in work produced per quantity of heat (D) Diesel engine normally operates at lower compression ratio than an Otto engine for an equal output of work

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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

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Last Answer : (A) Two temperatures only

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

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

For heat engine operating between two temperatures (T1>T2), what is the maximum efficiency attainable?  A. Eff = 1 – (T2/T1)  B. Eff = 1 - (T1/T2)  C. Eff = T1 - T2  D. Eff = 1 - (T2/T1)^2

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Last Answer : Eff = 1 – (T2/T1)

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

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Which statement of the second law of thermodynamics states that no heat engine can have a thermal efficiency of 100 percent?  A. Kelvin-Planck statement  B. Clausius statement  C. Kevin statement  D. Rankine statement

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Last Answer : Answer : d

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Description : What is the efficiency of the engine ?

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In a diesel engine the high temperature needed to ignite the fuel is achieved by – (1) using heat from exhaust (2) the battery (3) compressing air in the cylinders (4) an electrical spark

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The most efficient heat engine that can operate between two temperature reservoirs T1 and T2 is: w) jet engine x) internal combustion engine y) Carnot engine (pron: car-no) z) steam engine

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In a diesel engine the high temperature needed to ignite the fuel is achieved by (1) using heat from exhaust (2) the battery (3) compressing air in the cylinders (4) an electrical spark

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WHICH terms refers to the efficiency of a rockets engine?

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Supercharging of an IC engine is done so that the A. thermal efficiency increases B. power output increases C. speed of the engine increases D. power output decreases

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Morse test is conducted on the engine to calculate the mechanical efficiency of A. single cylinder CI engine B. single cylinder SI engine C. only on two stroke engines D. multi cylinder engine

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A 40 kW engine has a mechanical efficiency of 80 %. If the frictional power is assumed to be constant with load, what is the approximate value of the mechanical efficiency at 50 % of the rated load? (a) 45% (b) 55 % (c) 65% (d) 75%

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An engine produces 10 kW brake power while working with a brake thermal efficiency of 30%. If the calorific value of the fuel used is 40000 kJ/kg, then what is the fuel consumption? (a) 1.5 kg/hour (b) 3 kg/hour (c) 0.3 kg/hour (d) 1 kg/hour

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Ratio of actual indicated work to hypothetical indicated work in a steam engine is the (a) Indicated thermal efficiency (b) Friction factor (c) Mechanical efficiency (d) Diagram factor

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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

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