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

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

1 Answer

Answer :

ANSWER : C
by
selected by

Related questions

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 turbine, the fluid expands almost (A) Isothermally (B) Isobarically (C) Adiabatically (D) None of these

Description : In a turbine, the fluid expands almost (A) Isothermally (B) Isobarically (C) Adiabatically (D) None of these

Last Answer : (C) Adiabatically

A gas performs the maximum work, when it expands (A) Non-uniformly (B) Adiabatically (C) Isobarically (D) Isothermally

Description : A gas performs the maximum work, when it expands (A) Non-uniformly (B) Adiabatically (C) Isobarically (D) Isothermally

Last Answer : (C) Isobarically

In diesel engine, the fuel is ignited by a. spark b. injected fuel c. heat resulting from compressing air that is supplied for combustion d. ignitor

Description : In diesel engine, the fuel is ignited by a. spark b. injected fuel c. heat resulting from compressing air that is supplied for combustion d. ignitor

Last Answer : ANSWER c. heat resulting from compressing air that is supplied for combustion

Rotary compressors are used for delivering A. Small quantities of air at high pressure B. Large quantities of air at high pressure C. Small quantities of air at low pressure D. Large quantities of air at low pressure

Description : Rotary compressors are used for delivering A. Small quantities of air at high pressure B. Large quantities of air at high pressure C. Small quantities of air at low pressure D. Large quantities of air at low pressure

Last Answer : ANSWER : D

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

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

Last Answer : Process 1-2 : Constant volume process Process 2-3 : Constant temperature process (Isothermal process)

In a naturally aspirated diesel engine, the air is supplied by a A. supercharger B. centrifugal pump C. movement of engine piston D. reciprocating pump

Description : In a naturally aspirated diesel engine, the air is supplied by a A. supercharger B. centrifugal pump C. movement of engine piston D. reciprocating pump

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 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

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

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

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

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

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

Description : 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 ... ratio D. Its volumetric efficiency decreases with increasing clearance ratio and pressure ratio

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

Which one of the following types of impeller vanes are most commonly used in centrifugal type compressors? A. Forward curved B. Radial C. Backward curved D. Tangential

Description : Which one of the following types of impeller vanes are most commonly used in centrifugal type compressors? A. Forward curved B. Radial C. Backward curved D. Tangential

Last Answer : ANSWER : C

Explain construction and working of two stage reciprocating air compressors.

Description : Explain construction and working of two stage reciprocating air compressors.

Last Answer : Figure: Two Stage Reciprocating air compressor Construction and Working : It consists of two cylinders (L.P. and H.P.) with water cooled intercooler and air receiver. First of all fresh air is ... (ie second stage) from 3 to 4 is delivered by the compressor at pressure P3 & Temp T4.

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

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

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

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

Centrifugal compressors compared to reciprocating compressors (A) Require less space (B) Have quieter operation (C) Have lower operating costs (D) All (A), (B) and (C)

Description : Centrifugal compressors compared to reciprocating compressors (A) Require less space (B) Have quieter operation (C) Have lower operating costs (D) All (A), (B) and (C)

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

What Is The Difference Between A Rotary Screw Compressor And A Reciprocating Compressors?

Description : What Is The Difference Between A Rotary Screw Compressor And A Reciprocating Compressors?

Last Answer : A rotary screw compressor is one that utilizes two intermeshing helical rotors to trap a volume of air, then compress it to a higher pressure. Rotary screw compressors can be run at lower ... piston compressor (aka reciprocating) uses pistons driven by a crankshaft to deliver air at high pressure.

What is the effect of increase in altitude on the performance of single stage reciprocating compressors?

Description : What is the effect of increase in altitude on the performance of single stage reciprocating compressors? 

Last Answer : With the increase in altitude, there will be reduction in air pressure, which results in increase in compression ratio, leading to higher discharge temperature and reduced efficiency. 

List the advantages of keeping the discharge pressure for reciprocating compressors at minimum.

Description : List the advantages of keeping the discharge pressure for reciprocating compressors at minimum. 

Last Answer : Lower power consumption Less load on the piston rods and hence reduced maintenance costs Lower leakage losses

List the means of capacity control for reciprocating compressors.

Description : List the means of capacity control for reciprocating compressors. 

Last Answer : On/off control Load and unload control Multi-step control

What are the likely effects of using very cold water in intercoolers for reciprocating compressors?

Description : What are the likely effects of using very cold water in intercoolers for reciprocating compressors? 

Last Answer : Use of very cold water can result in condensation which may result in water entering the cylinder, thereby reducing valve life, accelerating wear and scoring of piston, piston rings and ... and cause rust which will result in abrasion during compressor operation and significantly reduce efficiency. 

Why inter-coolers are required for multi-stage reciprocating compressors?

Description : Why inter-coolers are required for multi-stage reciprocating compressors?  

Last Answer : The intercoolers reduce the temperature of air/gas discharged between stages. Ideally, the intake temperature at each stage should be the same as that at the first stage (referred to a perfect cooling), so that the volume of air to be compressed does not increase and hence reduced power consumption.

From base load operation and from achieving best specific energy consumption point of view, which of the following compressors are suitable? a) Single stage reciprocating compressors b) Centrifugal compressors c) Two stage reciprocating compressor d) Multi stage reciprocating compressor

Description : From base load operation and from achieving best specific energy consumption point of view, which of the following compressors are suitable? a) Single stage reciprocating compressors b) Centrifugal compressors c) Two stage reciprocating compressor d) Multi stage reciprocating compressor

Last Answer : b) Centrifugal compressors

From the point of lower specific energy consumption, which of the following compressors are suitable for part load operation? a) Two stage reciprocating compressors b) Centrifugal compressors c) Two stage screw compressor d) Single stage screw compressor

Description : From the point of lower specific energy consumption, which of the following compressors are suitable for part load operation? a) Two stage reciprocating compressors b) Centrifugal compressors c) Two stage screw compressor d) Single stage screw compressor

Last Answer : a) Two stage reciprocating compressors

Vertical type reciprocating compressors are used in the capacity range of _____ a) 50 – 150 cfm b) 200 – 500 cfm c) Above 10ooo cfm d) 10 – 50 cfm

Description : Vertical type reciprocating compressors are used in the capacity range of _____ a) 50 – 150 cfm b) 200 – 500 cfm c) Above 10ooo cfm d) 10 – 50 cfm 

Last Answer : a) 50 – 150 cfm

How do screw compressors differ from reciprocating ones?

Description : How do screw compressors differ from reciprocating ones?

Last Answer : All air compressors are divided into two types: reciprocating and screw, and many enterprises are faced with the problem of choosing a compressor. This choice affects not only the efficiency of the ... for screw compressor equipment. Based on materials from the site http://compressor.dukon.ru/ .

Total Air Temperature is: a. The maximum temperature attainable by the air when brought to rest, adiabatically b. The temperature indicated on the air temperature thermometer plus the ram rise c. The static air temperature minus the recovery factor d. The recovery factor plus the ram rise

Description : Total Air Temperature is: a. The maximum temperature attainable by the air when brought to rest, adiabatically b. The temperature indicated on the air temperature thermometer plus the ram rise c. The static air temperature minus the recovery factor d. The recovery factor plus the ram rise

Last Answer : a. The maximum temperature attainable by the air when brought to rest, adiabatically

Total Air Temperature is: a. The maximum temperature attainable by the air when brought to rest, adiabatically b. The temperature indicated on the air temperature thermometer plus the ram rise c. The static air temperature minus the recovery factor d. The recovery factor plus the ram rise

Description : Total Air Temperature is: a. The maximum temperature attainable by the air when brought to rest, adiabatically b. The temperature indicated on the air temperature thermometer plus the ram rise c. The static air temperature minus the recovery factor d. The recovery factor plus the ram rise

Last Answer : a. The maximum temperature attainable by the air when brought to rest, adiabatically

What horse power is required to isothermally compress 800 ft^3 of Air per minute from 14.7 psia to 120 psia?  A. 28 hp  B.108 hp  C.256 hp  D.13900 hp Formula: W= p1V1 ln (p1/p2) Power = dW / dt

Description : What horse power is required to isothermally compress 800 ft^3 of Air per minute from 14.7 psia to 120 psia?  A. 28 hp  B.108 hp  C.256 hp  D.13900 hp Formula: W= p1V1 ln (p1/p2) Power = dW / dt

Last Answer : 108 hp

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

Description : 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

Last Answer : (3) compressing air in the cylinders Explanation: Diesel engines use the heat of compressed air to ignite the fuel (intakes air, compresses it, then injects fuel). Diesel engines need high compression ratios to generate the high temperatures required for fuel auto ignition.

Interstage coolers are provided in a multistage compressor to (A) Save power in compressing a given volume to a given pressure (B) Cool the delivered air (C) Achieve the exact delivery pressure (D) None of these

Description : Interstage coolers are provided in a multistage compressor to (A) Save power in compressing a given volume to a given pressure (B) Cool the delivered air (C) Achieve the exact delivery pressure (D) None of these

Last Answer : (A) Save power in compressing a given volume to a given pressure

Thermo-compressor is commonly used for a) compressing hot air b) flash steam recovery c) distillation d) reverse compression of CO2

Description : Thermo-compressor is commonly used for a) compressing hot air b) flash steam recovery c) distillation d) reverse compression of CO2

Last Answer : flash steam recovery

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

Description : 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

Last Answer : compressing air in the cylinders

Classification of air compressor

Description : Classification Of Air Compressor

Last Answer : Air compressors are classified in several different ways, depending on the specific characteristics and features of the compressor. Here are a few common ways that air compressors are classified: ... range of sizes and capacities, from small, portable units to large, industrial-sized compressors.

Air refrigeration cycle is used in (a) domestic refrigerators (b) gas liquefaction (c)commercial refrigerators (d) Chillers

Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) gas liquefaction (c)commercial refrigerators (d) Chillers

Last Answer : Ans: b

The C.O.P. of a domestic refrigerator in comparison to domestic air conditioner will be (a) same (b) more (c) less (d) dependent on weather conditions

Description : The C.O.P. of a domestic refrigerator in comparison to domestic air conditioner will be (a) same (b) more (c) less (d) dependent on weather conditions

Last Answer : Ans: c

Air refrigeration cycle is used in (a) domestic refrigerators (b) commercial refrigerators (c) air conditioning (d) gas liquefaction

Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) commercial refrigerators (c) air conditioning (d) gas liquefaction

Last Answer : Ans: d

Air refrigeration operates on (a) Carnot cycle (b) Reversed Carnot cycle (c) Rankine cycle (d) Brayton cycle.

Description : Air refrigeration operates on (a) Carnot cycle (b) Reversed Carnot cycle (c) Rankine cycle (d) Brayton cycle.

Last Answer : Ans: d

Refrigeration in aeroplanes usually employs the following refrigerant (a) Co2 (b) Freon-11 (c) Freon-22 (d) Air

Description : Refrigeration in aeroplanes usually employs the following refrigerant (a) Co2 (b) Freon-11 (c) Freon-22 (d) Air

Last Answer : Ans: d