Which one of the following statements are correct for reciprocating air compressor? A. Its volumetric efficiency increases with increasing clearance ratio B. Its volumetric efficiency increases with pressure ratio C. Its volumetric efficiency does not vary with change in clearance ratio and pressure ratio D. Its volumetric efficiency decreases with increasing clearance ratio and pressure ratio

Which one of the following statements are correct for reciprocating air compressor? A. Its volumetric efficiency increases with increasing clearance ratio B. Its volumetric efficiency increases with pressure ratio C. Its volumetric efficiency does not vary with change in clearance ratio and pressure ratio D. Its volumetric efficiency decreases with increasing clearance ratio and pressure ratio  
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Which one of the following statement is not correct for the volumetric efficiency of a reciprocating air compressor? A. It decreases with increase in ambient temperature B. It increases with decrease in pressure ratio C. It increases with decrease in clearance ratio D. It decreases with increases in delivery pressure

Description : Which one of the following statement is not correct for the volumetric efficiency of a reciprocating air compressor? A. It decreases with increase in ambient temperature B. It increases with ... It increases with decrease in clearance ratio D. It decreases with increases in delivery pressure

Last Answer : ANSWER : A

Volumetric efficiency of a compressor without clearance volume A. Increases with increase in compression ratio B. Decreases wit increase in compression ratio C. Not dependent upon compression ratio D. Unpredictable

Description : Volumetric efficiency of a compressor without clearance volume A. Increases with increase in compression ratio B. Decreases wit increase in compression ratio C. Not dependent upon compression ratio D. Unpredictable

Last Answer : ANSWER : C

A reciprocating compressor is not suitable for use as a supercharger because: A. it runs at lower rpm B. the pressure ratio is high C. volumetric efficiency is high D. it is bulky and can handle small quantity of air

Description : A reciprocating compressor is not suitable for use as a supercharger because: A. it runs at lower rpm B. the pressure ratio is high C. volumetric efficiency is high D. it is bulky and can handle small quantity of air

Last Answer : ANSWER : D

In a reciprocating air compressor the compressor work per kg of air A. Increases as clearance volume increases B. Decreases as clearance volume increases C. Is independent of clearance volume D. Increases with clearance volume only of multistage compressor

Description : In a reciprocating air compressor the compressor work per kg of air A. Increases as clearance volume increases B. Decreases as clearance volume increases C. Is independent of clearance volume D. Increases with clearance volume only of multistage compressor

Last Answer : ANSWER : C

The clearance volume of the air compressor is kept minimum because A. It allows maximum compression to be achieved B. It greatly affects volumetric efficiency C. It results in minimum work D. It permits isothermal compression

Description : The clearance volume of the air compressor is kept minimum because A. It allows maximum compression to be achieved B. It greatly affects volumetric efficiency C. It results in minimum work D. It permits isothermal compression

Last Answer : ANSWER : B

In reciprocating air compressor the clearance ratio is given by A. B. C. D.

Description : In reciprocating air compressor the clearance ratio is given by A. B. C. D.

Last Answer : ANSWER : C

A large clearance volume in a reciprocating compressor results in A. Reduced volume flow rate B. Increased volume flow rate C. Lower suction pressure D. Lower delivery pressure

Description : A large clearance volume in a reciprocating compressor results in A. Reduced volume flow rate B. Increased volume flow rate C. Lower suction pressure D. Lower delivery pressure

Last Answer : ANSWER : A

A large clearance volume in reciprocating compressor results in A. reduced volume flow rate B. Increased volume flow rate C. Lower suction pressure D. Lower delivery pressure

Description : A large clearance volume in reciprocating compressor results in A. reduced volume flow rate B. Increased volume flow rate C. Lower suction pressure D. Lower delivery pressure

Last Answer : ANSWER : A

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

In a two stage reciprocating air compressor, the suction and delivery pressure are 1 and 4 bar respectively. For maximum efficiency the intercooler pressure is A. 1.5 bar B. 2 bar C. 2.5 bar D. 3 bar

Description : In a two stage reciprocating air compressor, the suction and delivery pressure are 1 and 4 bar respectively. For maximum efficiency the intercooler pressure is A. 1.5 bar B. 2 bar C. 2.5 bar D. 3 bar

Last Answer : ANSWER : B

With increase in compression ratio, the volumetric efficiency of air compressor (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease (depends on the suction pressure)

Description : With increase in compression ratio, the volumetric efficiency of air compressor (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease (depends on the suction pressure)

Last Answer : Option A

The ratio of indicated power to shaft power of the engine required to drive the compressor is called A. Compressor efficiency B. Volumetric efficiency C. Isothermal efficiency D. Mechanical efficiency

Description : The ratio of indicated power to shaft power of the engine required to drive the compressor is called A. Compressor efficiency B. Volumetric efficiency C. Isothermal efficiency D. Mechanical efficiency

Last Answer : ANSWER : D

The accumulation of carbon in a cylinder results in increase of A. clearance volume B. volumetric efficiency C. ignition time D. effective compression ratio

Description : The accumulation of carbon in a cylinder results in increase of A. clearance volume B. volumetric efficiency C. ignition time D. effective compression ratio

Last Answer : ANSWER : D

The accumulation of carbon in a cylinder results in increase of a. clearance volume b. volumetric efficiency c. ignition time d. effective compression ratio

Description : The accumulation of carbon in a cylinder results in increase of a. clearance volume b. volumetric efficiency c. ignition time d. effective compression ratio

Last Answer : ANSWER d. effective compression ratio

Volumetric efficiency of air compressor is of the order of A. 20% to 30 % B. 40% to 50% C. 60% to 70% D. 70% to 90%

Description : Volumetric efficiency of air compressor is of the order of A. 20% to 30 % B. 40% to 50% C. 60% to 70% D. 70% to 90%

Last Answer : ANSWER : D

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

Explain the factors affecting volumetric efficiency of reciprocating air compressor.

Description : Explain the factors affecting volumetric efficiency of reciprocating air compressor.

Last Answer : Factors affecting volumetric efficiency of reciprocating air compressor: 1) Clearance Volume 2) Restricted passage and leakage at inlet valves 3) Speed of rotation 4) Piston ring leakages ... wall, it get expanded, which decreases the charge taken in therefore volumetric efficiency decreases.

Which one of the following statements is correct? A. Reciprocating compressors are used to supply large quantities of air at a lower pressure ratio B. Centrifugal compressors are used to supply large quantities of air at a lower pressure ratio C. Centrifugal compressors are used to supply small quantities of air at a lower pressure ratio D. Centrifugal compressors cannot be run at high speed because of impeller, diffuser and casing.

Description : Which one of the following statements is correct? A. Reciprocating compressors are used to supply large quantities of air at a lower pressure ratio B. Centrifugal compressors are used to supply ... . Centrifugal compressors cannot be run at high speed because of impeller, diffuser and casing.

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

In a single stage reciprocating air compressor, the work done on air to compressor is from suction pressure to delivery pressure will be minimum when the compression is A. Isothermal process B. Adiabatic process C. Polytropic process D. Constant pressure process.

Description : In a single stage reciprocating air compressor, the work done on air to compressor is from suction pressure to delivery pressure will be minimum when the compression is A. Isothermal process B. Adiabatic process C. Polytropic process D. Constant pressure process.

Last Answer : ANSWER : A

The volumetric efficiency of the compressor ______ with the increase in altitude of place a) increases b) decreases c) does not change d) None

Description : The volumetric efficiency of the compressor ______ with the increase in altitude of place a) increases b) decreases c) does not change d) None

Last Answer : b) decreases

If the performance of diesel engine of different sizes, cylinder dimensions and power rating are to be compared, which of the following parameters can be used for such comparison? (a) Swept volume (b) Air fuel ratio (c) Specific brake fuel consumption (d) Volumetric efficiency

Description : If the performance of diesel engine of different sizes, cylinder dimensions and power rating are to be compared, which of the following parameters can be used for such comparison? (a) Swept volume (b) Air fuel ratio (c) Specific brake fuel consumption (d) Volumetric efficiency

Last Answer : Ans :c

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

In a single acting reciprocating compressor, the suction, compression and delivery of air takes place in A. One stroke B. Two stroke C. Three stroke D. Four stroke

Description : In a single acting reciprocating compressor, the suction, compression and delivery of air takes place in A. One stroke B. Two stroke C. Three stroke D. Four stroke

Last Answer : ANSWER : B

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

What is the relation between compression ratio (rk) and the efficiency of the Otto cycle? a. efficiency decreases with increase in compression ratio b. efficiency increases with increase in compression ratio c. efficiency is not affected by change in compression ratio d. none of the above

Description : What is the relation between compression ratio (rk) and the efficiency of the Otto cycle? a. efficiency decreases with increase in compression ratio b. efficiency increases with increase in compression ratio c. efficiency is not affected by change in compression ratio d. none of the above

Last Answer : ANSWER b. efficiency increases with increase in compression ratio

Work input to the air compressor with n as index of compression A. Increases with increase in value of n B. Decrease with increase in value of n C. remains same whatever the value of n D. first increase and then decreases with increase of value of n.

Description : Work input to the air compressor with n as index of compression A. Increases with increase in value of n B. Decrease with increase in value of n C. remains same whatever the value of n D. first increase and then decreases with increase of value of n.

Last Answer : ANSWER : A

How the net work to drive a compressor and its volumetric efficiency behave with increase in clearance volume ?

Description : How the net work to drive a compressor and its volumetric efficiency behave with increase in clearance volume ?

Last Answer : Work remains unaltered and volumetric efficiency decreases.

Air vessel provided in a reciprocating pump (A) Smoothens the flow by avoiding pulsations (B) Increases the volumetric efficiency of the pump (C) Saves the pump from the danger of cavitation (D) None of these

Description : Air vessel provided in a reciprocating pump (A) Smoothens the flow by avoiding pulsations (B) Increases the volumetric efficiency of the pump (C) Saves the pump from the danger of cavitation (D) None of these

Last Answer : (D) None of these

In a centrifugal compressor, an increase in speed at a given pressure ratio causes A. Increase in flow B. Decrease in flow C. Increase in efficiency D. Increase in flow and decrease in efficiency

Description : In a centrifugal compressor, an increase in speed at a given pressure ratio causes A. Increase in flow B. Decrease in flow C. Increase in efficiency D. Increase in flow and decrease in efficiency

Last Answer : ANSWER : D

The ratio of work done per cycle to the stroke volume of the compressor is known as A. Compressor capacity B. Compression ratio C. Compressor efficiency D. Mean effective pressure

Description : The ratio of work done per cycle to the stroke volume of the compressor is known as A. Compressor capacity B. Compression ratio C. Compressor efficiency D. Mean effective pressure

Last Answer : ANSWER : D

For a multistage compressor, the polytropic efficiency is A. the efficiency of all stages combined together B. the efficiency of one stage C. Constant throughout for all the stages D. a direct consequence of the pressure ratio

Description : For a multistage compressor, the polytropic efficiency is A. the efficiency of all stages combined together B. the efficiency of one stage C. Constant throughout for all the stages D. a direct consequence of the pressure ratio

Last Answer : ANSWER : C

In a centrifugal compressor an increase in speed at a given pressure ratio causes A. Increase in flow and increase in efficiency B. Increase in flow and decrease in efficiency C. Decrease in flow and increase in efficiency D. Decrease in flow and decrease in efficiency

Description : In a centrifugal compressor an increase in speed at a given pressure ratio causes A. Increase in flow and increase in efficiency B. Increase in flow and decrease in efficiency C. Decrease in flow and increase in efficiency D. Decrease in flow and decrease in efficiency

Last Answer : ANSWER : B

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%

In electronic fuel injection, there is improvement in the _____________ efficiency due to comparatively less resistance in the intake manifolds which will cause less pressure losses. a) mechanical b) volumetric c) overall d) none of the mentioned

Description : In electronic fuel injection, there is improvement in the _____________ efficiency due to comparatively less resistance in the intake manifolds which will cause less pressure losses. a) mechanical b) volumetric c) overall d) none of the mentioned

Last Answer : Answer: b Explanation: In electronic fuel injection, there is improvement only in the volumetric efficiency due to comparatively less resistance in the intake manifolds which will cause less pressure losses and no other efficiencies are hindered.

The domestic refrigerator uses following type of compressor (a) centrifugal (b) axial (c) miniature sealed unit (d) piston type reciprocating

Description : The domestic refrigerator uses following type of compressor (a) centrifugal (b) axial (c) miniature sealed unit (d) piston type reciprocating

Last Answer : Ans: d

Which one of the following types of compressor is mostly used for supercharging of IC engines? (a) Radial flow compressor (b) Axial flow compressor (c) Root blower (d) Reciprocating compressor

Description : Which one of the following types of compressor is mostly used for supercharging of IC engines? (a) Radial flow compressor (b) Axial flow compressor (c) Root blower (d) Reciprocating compressor

Last Answer : Ans : c

Compressor mostly used for supercharging of IC engine is A. Radial flow compressor B. Axial flow compressor C. Root blower compressor D. Reciprocating compressor

Description : Compressor mostly used for supercharging of IC engine is A. Radial flow compressor B. Axial flow compressor C. Root blower compressor D. Reciprocating compressor

Last Answer : ANSWER : A

Reciprocating compressor are provided with A. Simple disc/plate valve B. Poppet valve C. Spring-loaded disc valve D. Solenoid valve.

Description : Reciprocating compressor are provided with A. Simple disc/plate valve B. Poppet valve C. Spring-loaded disc valve D. Solenoid valve.

Last Answer : ANSWER : A

Which one of the following type of compressor is mostly used for supercharging of I.C engine A. Radial flow compressor B. Axial flow compressor C. Root blower D. Reciprocating compressor.

Description : Which one of the following type of compressor is mostly used for supercharging of I.C engine A. Radial flow compressor B. Axial flow compressor C. Root blower D. Reciprocating compressor.

Last Answer : ANSWER : C

The specific speed of a centrifugal compressor is generally A. less than that of reciprocating compressor B. independent of compressor type, but depends only on size of compressor C. higher than that of axial compressor D. more than specific speed of reciprocating compressor but less than axial compressor

Description : The specific speed of a centrifugal compressor is generally A. less than that of reciprocating compressor B. independent of compressor type, but depends only on size of compressor C. higher ... axial compressor D. more than specific speed of reciprocating compressor but less than axial compressor

Last Answer : ANSWER : C

Formation of frost on evaporator in refrigerator (a) results in loss of heat due to poor heat transfer (b) increases heat transfer rate (c) decreases compressor power. (d) can be avoided by proper design

Description : Formation of frost on evaporator in refrigerator (a) results in loss of heat due to poor heat transfer (b) increases heat transfer rate (c) decreases compressor power. (d) can be avoided by proper design

Last Answer : Ans: a

Clearance volume in compressor should be A. As large as possible B. As small as possible C. About 50% of swept volume D. About 100% of swept volume

Description : Clearance volume in compressor should be A. As large as possible B. As small as possible C. About 50% of swept volume D. About 100% of swept volume

Last Answer : ANSWER : B

Which one of the following methods can be adopted to obtain isothermal compression in an air compressor? A. Increasing the weight of the compressor B. Inter-stage heating C. Atmospheric cooling D. Providing appropriate dimensions to the cylinder

Description : Which one of the following methods can be adopted to obtain isothermal compression in an air compressor? A. Increasing the weight of the compressor B. Inter-stage heating C. Atmospheric cooling D. Providing appropriate dimensions to the cylinder

Last Answer : ANSWER : A

In a variable speed SI engine, the maximum torque occurs at the maximum (a) Speed (b) Brake power (c) Indicated power (d) Volumetric efficiency

Description : In a variable speed SI engine, the maximum torque occurs at the maximum (a) Speed (b) Brake power (c) Indicated power (d) Volumetric efficiency

Last Answer : Ans :d

Which one of the following is correct? A. In a multistage compressor adiabatic efficiency is less than stage efficiency B. In a multistage turbine adiabatic efficiency is less than the stage efficiency C. Preheat factor for a multistage compressor is greater than one D. Preheat factor does not affect the multistage compressor performance

Description : Which one of the following is correct? A. In a multistage compressor adiabatic efficiency is less than stage efficiency B. In a multistage turbine adiabatic efficiency is less than the stage ... compressor is greater than one D. Preheat factor does not affect the multistage compressor performance

Last Answer : ANSWER : A

The critical spark energy required to ignite a given mixture A. decreases with decreasing sparking voltage B. increases with decreasing sparking voltage C. increases with increasing sparking voltage D. decreases with increasing sparking voltage

Description : The critical spark energy required to ignite a given mixture A. decreases with decreasing sparking voltage B. increases with decreasing sparking voltage C. increases with increasing sparking voltage D. decreases with increasing sparking voltage

Last Answer : ANSWER : D

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

Description : 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

Last Answer : ANSWER : B

When humidity ratio of air ____ air is said to be dehumidified. A. increases B. decreases C. remains constant D. none of the mentioned

Description : When humidity ratio of air ____ air is said to be dehumidified. A. increases B. decreases C. remains constant D. none of the mentioned

Last Answer : ANSWER : B

In a simple carburetor, the air-fuel ratio increases when the A. density of air increases B. velocity of air increases C. velocity of air decreases D. density of air decreases

Description : In a simple carburetor, the air-fuel ratio increases when the A. density of air increases B. velocity of air increases C. velocity of air decreases D. density of air decreases

Last Answer : ANSWER : B