FLUID MECHANICS QUIZ

The hydraulic radius for flow in a rectangular duct of cross-sectional dimension H, W is

2HW/(H + W)²

√(HW/π)

HW/4(H + W)²

HW/2(H + W)²

TRUE ANSWER : ?
YOUR ANSWER : ?

Foot valves are provided in the suction line of a centrifugal pump to

Remove the contaminant present in the liquid

Avoid priming, every time we start the pump

Control the liquid discharge

Minimise the fluctuation in discharge

TRUE ANSWER : ?
YOUR ANSWER : ?

Prandtl mixing length is

Applicable to laminar flow problems

A universal constant

Zero at the pipe wall

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

The Stoke's stream function applies to the

Irrotational flow only

Cases of axial symmetry

Ideal/non-viscous fluids only

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

A double acting reciprocating pump compared to a single acting pump (of almost same size working under same pressure levels) would give almost double

Head

Discharge

None of these

Efficiency

TRUE ANSWER : ?
YOUR ANSWER : ?

For a stable equilibrium of a submerged body (where, G and B are centres of gravity & buoyancy respectively).

None of these

B is above G

G is above B

B & G coincide

TRUE ANSWER : ?
YOUR ANSWER : ?

If two capillary tubes of dia 0.5 mm and 1 mm are dipped in a pot containing mercury, then the rise of mercury is

Greater in 1 mm dia tube

Greater in 0.5 mm dia tube

Zero in both the tubes

Same in both the tubes

TRUE ANSWER : ?
YOUR ANSWER : ?

Velocity distribution for flow between two fixed parallel plates

Varies parabolically across the section

Is constant over the entire cross-section

None of these

Is zero at the plates and increases linearly to the midplane

TRUE ANSWER : ?
YOUR ANSWER : ?

A 2" gate valve fitted in a pipe is replaced by a similar globe valve. Pressure drop in gate valve was Δp. For the same discharge, the pressure drop across globe valve is

> Δp

Δp²

Δp

< Δp

TRUE ANSWER : ?
YOUR ANSWER : ?

Specific speed of a centrifugal pump relates it with another pump having the

Same speed

Geometrical similarity

Dynamic similarity

Same efficiency

TRUE ANSWER : ?
YOUR ANSWER : ?

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