Question with Answer of DRDO 2008 - 2009

 Question with Answer of DRDO 2008 - 2009 Exam :

1. Spur Gear are used for ____

transmitting power between two parallel shaft . 

2. In the case of a curved beam subjected to pure bending, which of the following is true ? 

Neutral axis coincides with the centroidal axis . 

3. Which of the following bearings are  terned as anti friction bearing ?

Ball and Rollar Bearing 

Frictional Bearing 

1. Angular Bearing

2. Rolling Element Bearing

3. Deep Groove Ball Bearing

4. Which of the following is a flexible coupling ? 

Oldham Coupling .

Oldham Coupling

5. Endurance limit of a component ____

decreases as the surface roughness  increses .

6. A discountinuity or jump in the shear force diagram occours whenever a beam is loaded by _____

a concentrated force .

7. When a solid circular shaft is in pure torsion and deforms elastically , the shearing stress in the shaft _____

Varies linearly with the radial distance from the axis of the shaft .

8. The linear relation between the stress and strain of a material is valid until____

Proportional Limit .

9. Which of the following can be the measure of ductility of a material ?

Percent reduction in area in tension test 

10. At the point of contraflexture of a beam __

Sign of curvature in the deflection curve charges .

11. A material has s Poisson's ratio of 0.5 . If a body is made of this material and subjected to external forces (within the elastic limit ) then the final volume of body is _____

equal to the initial volume of the body .

12. Hinge support is not capable of resisting ____

moment .

13. For any process , the second law of thermodynamics requires that the entropy change of the system be ____

Positive or zero 

14. For water boiling at constant pressure of 1 bar , the specific heat is ____

Zero 

15. An inventor claims to have constructed a device that rejects 300KJ of heat to a single reservoir while absorbing 300KJ of water during a single cycle of the device . This device violets ____

Only the first law of thermodynamics and no other laws .

16. A man sites on the floor by a fire burning at some distance at the same level . The mode of the heat transfer mainly responsible for the man receiving heat is ____

Radiation .

17. A spherical body with surface A1 is completely enclosed by another hollow body with inner surface A2 . The shape factor of A2 with respect to A1 is _____

0.5  

18. As thickness of insulation arround a heated cubic gradually increased from zero , heat transfer from the conductor _____

First increases and then decreases .

19. Arrangement of silver , air , aluminium and lead in the order of increasing thermal conductivity at room temperature yields . 

Air , Lead , Aluminium , Silver 

20. For a 2D rotational flow the Laplacian of the stream - function at any point in the flow field .

Equals Vorticity .

21. In passing through a standing normal shock - wave , a subsonic flow can not turn supersonic as it will not satisfy the ____

Second law of thermodynamics .

22. In the fully developed laminar flow through a horizontal pipe of constant cross section______

Static pressure decreases in the direction of flow . 

23. For a cylindrical wooden block completely submerged under water , the only correct statement among the following is ____

Buoyancy is independent of the vertical position and orientation .

24. In the converging part of a horizontal venturimeter ____

Static pressure gradually decreases .

25. A steady flow of fluid crossing a normal shock - wave undergoes a sudden rise in ___

Both static pressure and static  temperature .

26. Cavitation is a phenomenon observed ____

In all of centrifugal pumps , hydraulic reaction turbines and marine propellers .

27. In case of a gear pair with involute tooth profile , the pressure angle through out the contact is ____

Constant .

28. The number of links in a planar mechanism with revotute joints having 10 instantaneous centres is ______

5 .

n(n-1)/2 = 10

20 = n(n-1)

n = 5 , - 4 

29. Which one of the following statement is true ? 

In the principal planes , shear stresses are always zero but in the maximum shear planes , normal stresses may or may not be zero .

30. Radial pressure in a hydrodynamic bearing is ____

Maximum where film thickness is minimum .

31. Herringbone gears are used to ____

Eliminate axial thrust .

32. Consider the following statements about heat and work ____

• Both are path function .
• Heat is low grade energy and work is high grade energy .

33. A certain amount of fluid at temperature T1 is mixed with an equal amount of the same fluid at temperature T2 is an insulated container . With total fluid as the system _____

• Energy of the system is conserved .
• Entropy of the system increases .

34. For an ideal gas , the slope of the constant - volume line in the T-S diagram is _____

Lower than the slope of the constant pressure line .

35. Joule - Thomson coefficient for an ideal gas in a throattling process is _____

Equal to zero at all temperatures and pressures .

36. For the flow of a Newtonian fluid with constant density and viscosity . The governing equation is the _____

Navier - Strokes Equation .

37. In a two - dimensional flow of a viscous fluid , couette flow is defined for _____

Laminar flow between a fluid and a moving plate .

38. Blasius equation for a flat plate laminar boundary layer flow is a third order ____

Nonlinear partial differential equation .

39. Which one of the following properties drops across a normal shock ? 

Stagnation Pressure

40. Choose the correct statement for a quasi - one dimensional supersonic flow through a variable area duct .

Velocity increases when area increases .

Match List 1 and List 2 :

List 1	List 2
(a) Stanton Number	(A) Forced Convection
(b) Mach Number	(B) Compressibility
(c) Weber Number	(C) Surface Tension
(d) Grashof Number	(D) Free Convection
(e) Schmidt Number	(E) Mass Transfer