The hydraulic diameter of an annulus of inner and outer radii Ri and Ro respectively is___________________?

A. 4(Ro-Ri)
B. √(Ro-Ri)
C. 2(Ro-Ri)
D. Ro + Ri

Pressure drop for laminar fluid flow through a circular pipe is given by__________________?

A. 4f (L/D) (v2/2gc) ρ
B. 32 (μLV/gc D2)
C. 16/NRe
D. (fLρ/D) (v2/2gc)

In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is___________________?

A. The velocity of sound
B. Dependent on its cross-sectional area
C. Dependent on fluid viscosity
D. Dependent on fluid density

Minimum fluidisation velocity for a specific system depends upon the___________________?

A. Particle size
B. Fluid viscosity
C. Density of both the particle & the fluid
D. All A., B. and C.

The equivalent diameter for fluid flow through square cross section channel of side ‘x’, for pressure drop calculation purpose is given by____________________?

A. 4x
B. 2x
C. x
D. √x

The most economical flow control valve for use with large diameter pipes is a__________________?

A. Butterfly valve
B. Globe valve
C. Needle valve
D. None of these

The lift of a balloon is_________________?

A. Increased, as it rises to a higher altitude
B. Due to the weight of the atmospheric air, that it displaces
C. Not dependent on the temperature of the atmosphere
D. None of these

Unit of mass velocity is__________________?

A. kg/hr
B. kg/m2. hr
C. kg/m2
D. kg/m3. hr

For an ideal fluid flow, Reynolds number is___________________?

A. 2100
B. 100
C. 0
D. ∞

Permanent pressure loss in a well designed Venturimeter is about _____________ percent of the venturi differential?

A. 1
B. 10
C. 30
D. 50