21. An addition of manganese to aluminium results in the improvement of:


(a) Strength characteristics

(b) Corrosion resistance

(c) Hardernability

(d) Toughness system

Answer: (b)

22. A fluid when acted upon by a shear stress will deform

(a) When the applied shear stress is greater than the weight of the fluid

(b) When the applied shear stress is greater than the viscous strength of the fluid

(c) When the applied shear stress is greater than the yield strength of the fluid

(d) Independent of rate of shear strain

Answer: (d)

23. Statement (I): The radiation emitted by earth is of longer wavelength than that emitted by the sun.

Statement (II): Earth is at a lower temperature than the sun.

(a) Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

(b)Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I)

(c)Statement (I) is true but Statement (II) is false

(d)Statement (I) is false but Statement (II) is true

Answer: (a)

24. Consider the following statements:

1. Stream lines and path lines are instantaneous lines

2. Path lines and streak line are generated by passage of time

3. Path line can be found by time exposure of a marked particle

4. Stream lines, path lines and streak lines are identical in steady flow

Which of the above statements are correct?

(a) 1, 2 and 3 only

(b) 2, 3 and 4 only

(c) 1 and 4 only

(d) 1, 2, 3 and 4

Answer: (b)

25. A fluid jet discharging from 20 𝑚𝑚 diameter orifice has a diameter 17.5 𝑚𝑚 at its Vena-Contracta. The coefficient of contraction will be nearly:

(a) 0.98

(b) 0.88

(c) 0.77

(d) 0.67

Answer: (c)

26. A laminar boundary layer has a velocity distribution given by . The displacement thickness for this boundary layer will be

(a) 𝛿

(b) 𝛿/2

(c) 𝛿/3

(d) 𝜋𝛿/4

Answer: (b)

27. Consider the following statements:

1. In model testing, the same fluid must be used in prototype and also the model

2. Models should be smaller than prototype for geometric similarity

3. Geometrically similar boundaries do not necessarily imply kinematically homogeneous flows

4. Existence of geometric similarity does not imply dynamic similarity

Which of the above statements are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 3 and 4 only

(d) 1 and 4 only

Answer: (c)

28. Statement (I): For measurement of pressure at a section of a pipe running full, several openings round the periphery of pipe are often connected to a manometer through a common annulus.

Statement (II): Manometer connections to a pipe should be perpendicular to the axis of flow, edges smooth and free from burrs.

(a) Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

(b) Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I)

(c) Statement (I) is true but Statement (II) is false

(d) Statement (I) is false but Statement (II) is true

Answer: (b)

29. Consider the following statements regarding throttling process:

1. In throttling process there is neither heat transfer nor work transfer

2. In throttling process enthalpy before is equal to enthalpy after

3. Throttling process is an isentropic process

Which of the above statements are correct?

(a) 1 and 2 only

(b) 1 and 3 only

(c) 2 and 3 only

(d) 1, 2 and 3

Answer: (a)

30. Whenever a thermodynamic system undergoes a cycle, which of the following values are possible? (Notations have standard meaning)


(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (b)