64. The main assumption of Bernoulli's equation is :

A. The velocity of energy of liquid particle, across any cross-section of a pipe is uniform

B. No external force except the gravity acts on the liquid

C. There is no loss of energy of the liquid while flowing

D. All the above.

65. Euler's equation for the motion of liquids assumes that

A. fluid is viscous

B. fluid is homogeneous and incompressible

C. velocity of flow is non-uniform over the section

D. flow is unsteady along the stream line.

66. Euler's equation for motion of liquids, is given by

A. 1513 - gdz + vdv = 0

B. dp + dgz - vdv = 0

C. c-1132 + gdz + vdv = 0

D. pdp + gdz + vdv = O.

67. In a venturimeter, the divergent cone is kept

A. shorter than convergent cone

B. equal to covergent cone

C. longer than convergent cone

D. none of these.

68. To avoid the tendency of separation of liquid flow, the most suitable ratio of the diameters of the throat and the pipe, is

A. 1/4 to 1/3

B. 1/3 to ?

C. 1/2 to 3/4.

D. none of these.

69. Reynold number is the ratio of initial force and

A. viscosity

B. elasticity

C. gravitational force

D. surface tension.

70. Flow in pipes is laminar if Reynold number is

A. less than 2100

B. more than 3000

C. between 2100 and 3000

D. none of these.

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