The document contains 10 multiple choice questions about fluid mechanics concepts such as flow fields, path lines, streamlines, continuity equation, and steady incompressible flow. The questions cover topics like defining flow fields, describing path lines, conditions where streamlines/pathlines are identical, evaluating velocity given flow equations, determining local acceleration and satisfying the continuity equation, finding stream function equations, calculating velocity in a hypodermic needle apparatus, and representing steady incompressible flow.

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34. Ex 1. The flow field represented by the velocity vector 𝑽 = 𝒂𝒙 Ƹ
𝒊 + 𝒃𝒚𝟐 Ƹ
𝒋 + 𝒄𝒛𝒕𝟐෡
𝒌,
where a, b and c are constant, is
(a) three-dimensional and unsteady
(b) two-dimensional and steady
(c) two-dimensional and unsteady
(d) three-dimensional and steady

36. Ex 2. A path line describes
(a) The velocity direction at all points on the line
(b) The path followed by particles in a flow
(c) The path over a period of times of a single particle that has
passed out at a point
(d) The instantaneous position of all particles that have passed a
point.

38. Ex 3. Steam lines, streak lines, path lines are all identical in case of
(a) Uniform flow
(b) Non-uniform flow
(c) Both (a) & (b)
(d) Steady flow

40. Ex 4. A flow is defined by u = 2(1+t), v = 3(1+t) where t is the time. The
velocity at t = 2 is
(a) 6
(b) 9
(c) 10.82
(d) 6.7

42. Ex 5. The value of local acceleration in the x direction for flow with u =
2(1+t) is given by
(a) 0
(b) 2t
(c) 2
(d) t

44. Ex 6. The continuity equation is satisfied by
(a) u = A sin xy, v = – A sin xy
(b) u = x + y, v = x – y
(c) u = 2x2 + cy, v = 3y2
(d) u = x + 2y, v = 2x + y

46. Ex 7. The continuity equation (for a fluid)
𝝏𝝆
𝝏𝒕
+
𝝏
𝝏𝒙
(𝝆𝒖) +
𝝏
𝝏𝒚
(𝝆𝒗) +
𝝏
𝝏𝒙
(𝝆𝒘) = 𝟎
Where, is the density and u, v and w are the velocity components along x, y
and respectively, is valid for
(a) Incompressible flows only
(b) Steady flows only
(c) Newtonian fluids only
(d) Any general fluid

48. Ex 8. The velocity in m/s at a point in a two dimensional flow is given
as 𝐯 = 𝟑 Ƹ
𝐢 + 𝟓 Ƹ
𝐣. The equation of the system line passing through the
point (x,y) is
(a) 5dx – 3dy = 0
(b) 3x + 5y = 0
(c) 3dx + 2dy = 0
(d) xy = 15

50. Ex 9. The piston of a hypodermic apparatus (figure below shown) is
being withdrawn at 7.5 mm/sec, air leaks in to barrel (as the piston
moves up) at the volume rate 20 mm3/sec. What is the velocity of the
blood flow in the needle from blood vein?
(a) 0.65 m/sec
(b) 0.75 m/sec
(c) 0.95 m/sec
(d) 1.33 m/sec

52. Ex 10. Which of the following represents steady incompressible flow?
(a) u = 4xy + 2y2, v = 6xy + 3x2
(b) u = x2 + y2, v = - 2xy + 7
(c) u = x/y , v = y/x
(d) u = 2x + y, v = 4y + x

54. Thank you!
Use Code: LAMIYA10