611. 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

612. 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

613. 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

614. For an ideal fluid flow, Reynolds number is___________________?
A. 2100
B. 100
C. 0
D. ∞

615. Permanent pressure loss in a well designed Venturimeter is about _____________ percent of the venturi differential?
A. 1
B. 10
C. 30
D. 50

616. Air vessel provided in a reciprocating pump is for__________________?
B. Making the friction in pipe uniform
D. None of these

617. For water, when the pressure increases, the viscosity_________________?
A. Also increases
B. Decreases
C. Remain constant
D. First decreases, and then increases

618. Foot valve provided in the pump is a ______________ valve?
A. Direction control
B. Back pressure
C. Relief
D. Pressure reduction

619. For the production of very high vacuum, a _____________ pump is normally used?
A. Diffusion
B. Centrifugal
C. Jet ejector
D. Piston

620. Bernoulli’s equation is dependent on the__________________?
A. First law of thermodynamics
B. Third law of thermodynamics
C. Law of conservation of momentum
D. None of these

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