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 : 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 : 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 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 vapour compression cycle using NH3 as refrigerant, initial charge is filled at (a) suction of compressor (b) delivery of compressor (c) high pressure side close to receiver (d) low pressure side near receiver
Last Answer : Ans: c
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
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
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
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
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
Description : For a two stage compressor, the ratio of diameter of low pressure cylinder to high pressure cylinder is equal to A. Square of the ratio of final pressure to initial pressure B. The ratio of ... final pressure to initial pressure D. Cube root of the ratio of final pressure to initial pressure
Description : The suction pipe diameter of refrigerating unit compressor in comparison to delivery side is (a) bigger (b) smaller (c) equal (d) smaller/bigger depending on capacity
Last Answer : Ans: a
Description : In multi stage compressor, the isothermal compression is achieved by A. Employing intercooler B. By constantly cooling the cylinder C. By running compressor at very slow speed D. By insulating 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
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
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
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 : For obtaining high COP, the pressure range of compressor should be (a) high (b) low (c) optimum (d) any value
Last Answer : Ans: b
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 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 : 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 : 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 : 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
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
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
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.
Description : Reduction in the delivery pressure of a Compressor working at 7 bar, by 1 bar would reduce the power consumption by a) 6 to 10 % b) 2 to 3 % c) 12 to 14 % d) None of the above
Last Answer : a) 6 to 10 %
Description : A typical personal computer used for business purposes would have of RAM. A) 4 KB B) 16 K C) 64 K D) 256 K
Last Answer : Answer : D
Description : EBCDIC can code up to how many different characters? A) 256 B) 16 C) 32 D) 64
Last Answer : Answer : A
Description : The midrange frequency range of sound is from A. 256 to 2048 Hz B. 2048 to 4096 Hz C. 512 to 2048 Hz D. 16 to 64 Hz
Last Answer : A. 256 to 2048 Hz
Description : EBCDIC can code up to how many different characters? a. 256 b. 16 c. 32 d. 64
Last Answer : 256
Description : Compute the refractive index when the dielectric constant is 256 in air. a) 2562 b) 16 c) 256 d) 64
Last Answer : b) 16
Description : A typical personal computer used for business purposes would have… of RAM. a. 4 KB b. 16 K c. 64 K d. 256 K
Last Answer : d. 256 K
Last Answer : a. 256
Description : Insert the missing number in the following series: 4 16 8 64 ? 256 (A) 16 (B) 24 (C) 32 (D) 20
Last Answer : Answer: A Square root of 16 is 4, Square root of 64 is 8, Therefore Square root of 256 is 16.
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 coefficient of performance is the ratio of the refrigerant effect to the (a) heat of compression (b) work done by compressor (c) enthalpy increase in compressor (d) all of the above
Description : Where does the lowest temperature occur in a vapour compression cycle ? (a) condenser (b) evaporator (c) compressor (d) expansion valve
Description : In a refrigeration cycle, the flow of refrigerant is controlled by (a) compressor (b) condenser (c) evaporator (d) expansion valve
Description : In vapour compression refrigeration system, refrigerant occurs as liquid between (a) condenser and expansion valve (b) compressor and evaporator (c) expansion valve and evaporator (d) compressor and condenser
Description : In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to (a) collect liquid refrigerant and prevent it from going to compressor (b) detect liquid in vapour (c) superheat the vapour (d) increase refrigeration effect
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
Description : One of the purposes of sub-cooling the liquid refrigerant is to (a) reduce compressor overheating (b) reduce compressor discharge temperature (c) increase cooling effect (d) ensure that only liquid and not the vapour enters the expansion (throttling) valve
Description : The higher temperature in vapour compression cycle occurs at (a) compressor discharge. (b) expansion valve (c) evaporator (d) condenser discharge
Description : Presence of moisture in a refrigerant affects the working of (a) compressor (b) condenser (c) evaparator (d) expansion valve.
Description : The domestic refrigerator uses following type of compressor (a) centrifugal (b) axial (c) miniature sealed unit (d) piston type reciprocating