# Important Questions on Diploma Mechanical Engineering

Interested users can download the Important Questions on Diploma Mechanical Engineering from the links enclosed below. Download the Last 5 Years Important Questions on Diploma Mechanical Engineering Solved along with the Answers of each question. This Important Questions on Diploma Mechanical Engineering may vary from the Actual paper. Use the Important Questions on Diploma Mechanical Engineering as a reference for the exam preparation. Check the Important Questions on Diploma Mechanical Engineering from this page.

## Diploma Mechanical Engineering Important Questions Paper

1. If fluid is incompressible and it is steady then its mass is
(a) increasing
(b) decreasing
(c) same
(d) conserved

2. According to the equation of continuity, when water falls its speed increases, while its cross-sectional area
(a) Increases
(b) Decreases
(c) remain same
(d) different

3. The highest point of syphon is called as
(a) syphon top
(b) summit
(c) reservoir
(d) none of these

4. As an incompressible fluid moves through a restriction,
(a) Velocity decreases and pressure increases
(b) Velocity increases and pressure increases
(c) Velocity increases and pressure remains the same
(d) Velocity decreases and pressure remains the same

5. For the measurement of flow rate of liquid, the method used is
(a) Conveyor-based methods
(b) Bourdon tube
(c) Coriolis method
(d) Thermal mass flow measurement

6. The pattern of flow in the boundary layer is judged by the
(a) Reynolds number
(b) Fourier number
(c) Peclet number
(d) Grashof number

7. The discharge in an open channel corresponding to critical depth is
(a) Zero
(b) Minimum
(c) Maximum
(d) None of these

8. Which type of nozzle is used in a steam turbine
(a) Convergent
(b) Divergent
(c) Convergent-divergent
(d) None

9. A body floats in stable equilibrium
(a) when the metacentre is above C.G.
(b) when its metacentric height is zero
(c) when its C.G. is below its center of buoyancy
(d) metacentre has nothing to do with position of C.G. for determining stability

10. Capillary action is due to the
(a) surface tension
(b) cohesion of the liquid
(c) adhesion of the liquid molecules and the molecules on the surface of a solid
(d) all of these

11. Heat transfer takes place as per –
(a) zeroth law of thermodynamics
(b) first law of thermodynamic
(c) second law of the thermodynamics
(d) Kirchoff’s law

12. Metals are good conductors of heat because
(a) their atoms collide frequently
(b) their atoms-are relatively far apart
(c) they contain free electrons
(d) they have high density

13. The flow on two sides of a normal shock wave is
(a) Subsonic
(b) Sonic
(c) Supersonic
(d) supersonic on one side and subsonic on the other side

14. Separation of flow occurs when pressure gradient
(a) becomes negative
(b) changes abruptly
(c) tends to approach zero
(d) reduces to a value when vapor formation starts

15. The rate of energy transferred by convection to that by conduction is called
(a) Stanton number
(b) Nusselt number
(c) Biot number
(d) Peclet number

16. Which statement is true regarding steady state condition?
(a) There is a variation in temperature in the course of time
(b) Heat exchange is constant
(c) It is a function of space and time coordinates
(d) Internal energy of the system changes

17. Thermal conductivity of the same material varies with
(a) the thickness of the material
(b) the temperature of the material
(c) both (a) & (b)
(d) thermal conductivity of the same material does not vary at all

18. In the process of heat transfer through extended surfaces or fins, the entire surface area is at
(a) the same constant temperature
(b) different temperatures
(c) maximum base temperature
(d) minimum temperature

19. Thermal diffusivity is
(a) a dimensionless parameter
(b) function of temperature
(c) used as mathematical model
(d) a physical property of the material

20. A non-dimensional number generally associated with natural convection heat transfer is
(a) Grashoff number
(b) Nusselt number
(c) Weber number
(d) Prandtl number

21. LMTD in case of counter flow heat exchanger as compared-to parallel flow heat exchanger is
(a) Higher
(b) Lower
(c) Same
(d) depends on the area of heat exchanger

22. According to Stefan-Boltzmann law, ideal radiators emit radiant energy at a rate proportional to
(a) absolute temperature
(b) square of temperature
(c) fourth power of absolute temperature
(d) fourth power of temperature

23. Which one is having highest value of overall heat transfer coefficient?
(a) Feed water heaters
(b) Steam condensers
(c) Alcohol condensers
(d) Ammonia condensers

24. In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the
(a) Reynold’s number
(b) Grashoff’s number
(c) Reynold’s number, Grashoff’s number
(d) Prandtl number, Grashoff’s number

25. Forced convection in a liquid bath is caused by
(a) Intense stirring by an external agency
(b) Molecular energy interactions
(d) Flow of electrons in a random fashion

## More Question Set on Mechanical Engineering Diploma MCQs from Various Exam

 Model Question Old Question Sample Papers Mock Test Practice Set Question Bank Important Questions Test Papers Typical Questions Selected Questions

26. The mass transfer rate is independent of
(a) Turbulence effect
(b) Physical properties
(c) Chemical properties
(d) none of these

27. Shape factor for plane wall is equal to
(a) A/d
(b) 2A/d
(c) 3A/d
(d) 4A/d

28. Which of the following is NOT a type of heat pump?
(a) vapour compression type
(b) vapour absorption type
(c) both (a) & (b)
(d) none of these

29. During a refrigeration cycle, heat is rejected by the refrigerant in a
(a) Condenser
(b) Compressor
(c) Evaporator
(d) expansion valve

30. Which one of the following is a CFC refrigerant?
(a) R 744
(b) R 290
(c) R 502
(d) R 718

31. In a dry evaporator, refrigerant at the outlet is
(a) in the wet state
(b) saturated state
(c) super-heated state
(d) None

32. The presence of which of the following units in a vapor compression system is adversely affected by the presence of moisture?
(a) Condenser
(b) Expansion valve
(c) Evaporator
(d) Compressor

33. On a psychrometric chart cooling and humidification process using spray can be shown by
(a) horizontal line
(b) vertical line
(c) line parallel to dry bulb temperature lines
(d) line parallel to wet bulb temperature lines

34. During sensible heating of moist air, enthalpy
(a) Increases
(b) Decreases
(c) remains constant
(d) none of these

35. Which of the following cycles uses air as the refrigerant
(a) Ericsson
(b) Stirling
(c) Carnot
(d) Bell-coleman

36. The COP of a domestic refrigerator
(a) is less than 1
(b) is more than 1
(c) is equal to 1
(d) depends upon the make

37. Which of the following refrigerants has lowest freezing point
(a) Freon-12
(b) NH3
(c) CO2
(d) Freon-22

38. In a bomb calorimeter, the fuel burns at constant
(a) Volume
(b) Pressure
(c) Temperature
(d) entropy

39. Multistage centrifugal pumps are used to obtain
(a) high discharge
(c) pumping of viscous fluids
(d) high head and high discharge

40. Indicator diagram of a reciprocating pump is a graph between
(a) pressure in cylinder vs swept volume
(b) flow vs swept volume
(c) flow vs speed
(d) pressure vs speed

41. Francis, Kaplan and propeller turbines fall under the category of
(a) Impulse turbines
(b) Reaction turbines
(c) Axial flow turbines
(d) Mixed flow turbines

42. Comparing fire tube and water tube boilers, which boiler can produce comparatively higher pressure steam than another for the same capacity?
(a) fire tube boiler
(b) water tube boiler
(c) both can produce steam at same pressure for the same capacity
(d) none of these

43. For very high discharge at low pressure such as for flood control and irrigation applications, following type of pump is preferred
(a) Centrifugal
(b) axial flow
(c) reciprocating
(d) mixed flow

44. Low specific speed of a pump implies it is
(a) centrifugal pump
(b) mixed flow pump
(c) axial flow pump
(d) any one of these

45. Equivalent evaporation is the amount of water evaporated in a boiler from and at
(a) 0°C
(b) 100°C
(c) saturation temperature at given pressure
(d) room temperature

46. The second law of thermodynamics deals with
(a) direction of process and quality of energy
(b) energy balance
(c) balance of internal energy
(d) system efficiency

47. Fourier law of heat conduction is based on the assumption that
(a) Heat flow through a solid is one dimensional
(b) Heat flow is in steady state
(c) Both (a) and (b)
(d) None of these

48. Work is a
(a) point function
(b) path function
(c) depends on the state
(d) none of these

49. The type of pair formed by two elements which are so connected that one is constrained to turn or revolve about a fixed axis of another element is known as
(a) turning pair
(b) rolling pair
(c) sliding pair
(d) spherical pair

50. Pitch point on a cam is
(a) any point on pitch curve
(b) the point on cam pitch curve having the maximum pressure angle
(c) any point on pitch circle
(d) the point on cam pitch curve having the minimum pressure angle