1. The compressor capacity with decrease in suction temperature_________________?
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A. decreases

B. remains unaffected

C. increases upto certain limit and then decreases

D. may increase or decrease depending on compressor capacity

E. increases
2. Which is false statement about air receivers ___________________?
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A. These are used to dampen pulsations ,

B. These act as reservoir to- take care of sudden demands

C. These increase compressor efficiency

D. These knock out some oil and moisture

E. These reduce frequent on/off operation of compressors

3. Isothermal compression efficiency, even when running at high speed, can be approached by using A. multi-stage compression B. cold water spray C. both A. and B. above D. fully insulating the cylinder E. high stroke_________________?
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A. thermal compression efficiency, even when running at high speed, can be approached by using

B. multi-stage compression

C. cold water spray

D. both A. and B. above

E. fully insulating the cylinder

F. high stroke

4. What will be the volume of air at 327C if its volume at 27C is 1.5 m3/mt ?
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A. 18 m3/mt

B. 1.5 m3/mt

C. 0.75 m3/mt

D. 3 m3/mt

E. 6 m3/mt

5. For pipes, laminar flow occurs when Roynolds number is__________________?
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A. less than 4000

B. none of the above

C. between 2000 and 4000

D. less than 2000

E. more than 4000

6. After-cooler is used to__________________?
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A. cause moisture and oil vapour to drop out

B. cool the air

C. reduce volume

D. decrease the delivery temperature for ease in handling

E. increase pressure

7. Inter cooling in compressors__________________?
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A. is the standard practice for big compressors

B. prevents compressor jacket running very hot

C. cools the delivered air

D. results in saving of power in compressing a given volume to given pressure

E. enables compression in two stages

8. Reciprocating air compressor is best suited for___________________?
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A. large quantity of air at high pressure

B. large quantity of air at low pressure

C. small quantity of air at low pressure

D. any one of the above

E. small quantity of air at high pressure

9. Ratio of indicated H.P. and brake H.P. is known as_________________?
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A. volumetric efficiency

B. adiabatic efficiency

C. relative efficiency

D. mechanical efficiency

E. isothermal efficiency

10. If three forces acting in different planes can be represented by a triangle, these will be in________________?
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A. none of the above

B. unpredictable

C. partial equilibrium

D. full equilibrium

E. non-equilibrium
11. The ratio of work doen per cycle to the swept volume in case of compressor is called ______________?
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A. mean effective pressure

B. compression index

C. compressor effectiveness

D. compressor efficiency

E. compression ratio

12. Which of the following is not the unit of power ?
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A. hp (horse power)

B. kcal/kg sec

C. kW (kilowatt)

D. kg m/sec

E. kcal/sec

13. Volumetric efficiency of a compressor without clearance volume________________?
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A. unpredictable

B. is not dependent upon compressin ratio

C. may increase/decrease depending on compressor capacity

D. decreases with increase in compression ratio

E. increases with increase in compression ratio

14. If two equal forces of magnitude P act at an angle 9, their resultant will be________________?
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A. 2P tan 9/2

B. Psin 9/2

C. IP cos 9/2

D. P/2 cos 9/2

E. IP sin 9/2

15. Metacentre is the point of intersection of _________________________?
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A. buoyant force and the center line of body

B. none of the above

C. all of the above

D. mid point between e.g. and center of buoyancy

E. vertical upward force through e.g. of body and center line of body

16. Clearance volume in actual reciprocating compressors is essential __________________?
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A. to accommedate Valves in the cylinder head

B. to avoid mechanical bang of piston with cylinder head

C. to provide cushioning effect

D. to attain high volumetric efficiency

E. to provide cushioning effect and also to avoid mechanical bang of piston with cylinder head
17. Which of the following is the unit of kinematic viscosity _________________?
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A. poise

B. stoke

C. pascal

D. faraday

E. none of the above

18. Volumetric efficiency of a compressor with clearance volume ________________?
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A. decreases with increase in compression ratio

B. in not dependent upon compression ratio

C. increases with increase in compression ratio

D. unpredictable

E. may increase/decrease depending on compressor capacity

19. A pair of smiths tongs is an example of the lever of__________________?
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A. third order

B. second order

C. first order

D. zeioth order

E. fourth order

20. Which is false statement about multistage compression ?
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A. Outlet temperature is reduced

B. Power consumption per unit of air delivered is low

C. It is best suited for compression ratios around 7:1

D. Volumetric efficiency is high

E. The moisture in air is condensed in the intercooler

21. Center of buoyancy is the___________________?
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A. e.g. of floating body

B. none of the above

C. center of pressure of displaced volume

D. centroid of the displaced volume of fluid

E. does not exist

22. In a forced vortex, the velocity of flow everywhere within the fluid is__________________?
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A. zero

B. unpredictable

C. non-zero finite

D. minimum

E. maximum

23. Normal depth in open channel flow is the depth of flow corresponding to_______________?
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A. laminar flow

B. unsteady flow

C. uniform flow

D. critical flow

E. steady flow

24. Poise is the unit of________________?
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A. capillarity

B. surface tension

C. buoyancy

D. shear stress in fluids

E. viscosity
25. Maximum work is done in compressing air when the compression is_________________?
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A. polytropic

B. isothermal

C. adiabatic

D. none of the above

E. any one of the above

26. 1 m of air at atmospheric condition weighs approximately__________________?
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A. 2.2 kg

B. 3.2 kg

C. 0.5 kg

D. 1.0 kg

E. 1.3 kg
27. An ideal air compressor cycle without clearance on p-v diagram can be represented by following processes________________?
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A. two adiabatic, one isobaric and one constant volume

B. two isobaric, two adiabatic and one constant volume

C. one adiabatic, one isobaric and two constant volume

D. one adiabatic, two isobaric, and one constant volume

E. two adiabatic and two isobaric

28. Compression efficiency is compared against_____________________?
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A. ideal compression

B. adiabatic compression

C. isothermal compression

D. botii isothermal and adiabatic compression

E. isentropic compression

29. The work done per unit mass of air in compression willbe least when n is equal to______________?
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A. 1

B. 1.3

C. 1.2 ,

D. 1.4

E. 1.5

30. Hot wire anemometer is used to measure_______________?
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A. pressure intensity of gas

B. pressure intensity of liquid

C. discharge

D. velocity of gas
31. Isothermal compression effeicency can be attained by running the compressor__________________?
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A. at very slow speed

B. at very high speed

C. isothermally

D. at zero speed

E. at average speed

32. Standard air is the air at_____________________?
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A. 15C and 1 kg/cm2

B. 0C and standard atmospheric conditions

C. 20C and 1 kg/cm2 and relative humidity 36%

D. atmospheric conditions at any specific location

E. 25C, 1 kg/cm2 and RH of 60%.

33. Volumetric efficiency of air compressors is of the order of________________?
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A. 40-50%

B. 60-70%

C. 90-100%

D. 70-90%

E. 20-30%

34. The- most efficient method of compressing air is to compress it_________________?
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A. adiabatically

B. isochronically

C. isentropically

D. isothermally

E. as per law pV

35. Which of the following do not have identical dimensions ?
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A. Momentum and impulse

B. Torque and energy

C. Moment of a force and angular momentum

D. Kinetic energy and potential energy

E. Torque and work

36. Which of the following is not the unit of pressure ?
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A. kg/cm

B. atmosphere

C. ata

D. newton

E. mm of wcl

37. Barometer is used to measure__________________?
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A. atmospheric pressure

B. very low pressure

C. difference of pressure between two points

D. pressure in pipes, channels etc.

E. rain level

38. Ratio of compression is the ratio of__________________?
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A. absolute discharge pressure to the ab-solute intake pressure

B. gauge discharge pressure to the gauge intake pressure

C. none of the above

D. pressures at discharge and suction cor-responding to same temperature

E. stroke volume and clearance volume

39. A model of a reservior is drained in 4 mts by opening the sluice gate. The model scale is 1: 225. How long should it take to empty the prototype ?
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A. 900 minutes

B. 4 (225)1/3 minutes

C. 4 minutes

D. 4 x V225 minutes

E. 4 x (225)3/2 minutes

40. Isothermal compression though most efficient, but is not -practicable because_________________?
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A. compressor has to run at very slow speed to achieve it

B. it requires cylinder to be placed in water

C. ityrequires very big cylinder

D. it does not increase pressure much

E. it is impossible in practice

41. The clearance volume of the air compressor is kept minimum because____________________?
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A. it permits isothermal compression

B. it greatly affects volumetric efficiency

C. it results in minimum work

D. none of the above

E. it allows maximum compression to be achieved

42. Volumetric efficiency is_____________________?
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A. reciprocal of compression ratio

B. the ratio of the air actually delivered to the amount of piston displacement

C. the ratio of stroke volume to clearance volume

D. index of compressor performance

E. proportional to compression ratio

43. The capacity of a compressor is 5 m /mih. 5 m /min refers to_______________?
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A. compressed air at delivery pressure

B. air sucked

C. free air

D. compressed air

E. standard air

44. The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is as per the principle of__________________?
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A. independence of forces

B. dependence of forces

C. balance of force

D. resolution of forces

E. forces

45. The net work input required for compressor with increase in clearance volume_____________________?
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A. increases

B. remains same

C. unpredictable

D. decreases

E. increases/decreases depending on com-pressor capacity

46. The pressure and temperature conditions of air at the suction of compressor are_________________?
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A. slightly more than atmospheric

B. atmospheric

C. pressure slightly more than atmospheric and temperature slightly less than atmospheric

D. slightly less than atmospheric

E. pressure sightly less than atmospheric and temperature slightly more than atmospheric
47. Cylinder clearance in a compressor should be _________________?
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A. about 100% of swept volume

B. as small as possible

C. as large as possible

D. about 50% of swept volume

E. none of the above

48. All the terms of energy in Bernoullis equation have dimension of_______________?
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A. work

B. mass

C. time

D. length

E. energy

49. Property of a fluid by which molecules of different kinds of fluids are attracted to each other is called________________?
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A. viscosity

B. adhesion

C. cohesion

D. surface tension

E. compressibility

50. The fluid forces considered in the Navier Stokes equation are__________________?
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A. gravity, pressure and turbulent

B. gravity, pressure and viscous

C. gravity, viscous and turbulent

D. none of the above

E. pressure, viscous and turbulent