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  

1 Answer

Answer :

ANSWER : C

Related questions

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

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

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

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

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

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

Last Answer : ANSWER : C

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Description : Intercooling in multistage compression is done A. To cool the air during compression B. To cool the air at delivery C. To enable compression in two stages D. To minimize the work of compression

Last Answer : ANSWER : D

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

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

Description : Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.

Last Answer : Ans: d

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

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

Description : The volume of air delivered by the compressor is called A. Free air delivery B. Compressor capacity C. Swept volume D. Mean effective pressure

Last Answer : ANSWER : B

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%

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

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

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

Last Answer : ANSWER : C

Description : The pressure rise in the impeller of centrifugal compressor is achieved by A. the decrease in volume and diffusion action B. the centrifugal action and decrease in volume C. the centrifugal and diffusion action D. the centrifugal and push pull action

Last Answer : ANSWER : D

Description : The actual volume of fresh charge admitted in 4-stroke petrol engine is A. equal to stroke volume B. equal stroke volume and clearance volume C. less than stroke volume D. more than stroke volume

Last Answer : ANSWER : C

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

Description : In compression ignition (CI) engine, the compression ratio is a. Cylinder volume / Clearance volume b. Swept Volume / Cylinder Volume c. Clearance volume / Cylinder volume d. Cylinder volume / Swept volume (Ans:a)

Last Answer : In two stroke engine there is one power stroke in _____ of crankshaft rotation. a. 90° b. 180° c. 270° d. 360° (Ans:d)

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

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

Description : What is the formula for compression (rk) ratio of the Otto cycle? a. rk = Volume of cylinder at the beginning of compression / Volume of cylinder at the end of compression b. rk = Volume of cylinder ... c. rk = Volume of cylinder at the end of compression / clearance volume d. none of the above

Last Answer : ANSWER a. rk = Volume of cylinder at the beginning of compression / Volume of cylinder at the end of compression

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

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

Description : The volume of standard air is _____ m3/kg of dry air. a. 0.533 b. 0.633 c. 0.733 d. 0.833 e. 0.933

Last Answer : Answer: D

Description : The specific volume of air is expressed as the volume of: a. 1 kg of air at 101.325 kPa in cm3 b. 0.833 kg of air at standard pressure and temperature in m3 c. 1 kg of air at 101.325 ... d. 1 g of air occupied at any temperature and pressure e. 1 kg of air, regardless of temperature and pressure

Last Answer : Answer: C

Description : Standard air is the: a. Mass of 1 cubic meter of dry air at 20°C and atmospheric pressure b. Mass of a cubic meter of air at atmospheric conditions c. Volume of air at ambient temperature and atmospheric pressure ... pressure at sea level or 101.325 kPa e. Volume of 1 kg of air at 15°C and 100 kPa

Last Answer : Answer: D

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.

Description : The maximum delivery pressure in a rotary air compressor is A. 10 bar B. 20 bar C. 30 bar D. 50 bar

Last Answer : ANSWER : A

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