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050/23

The ratio of hydrodynamic to thermal boundary layer thickness varies as
A) root of Prandtl number B) one-third of Prandtl number
C) two-third power of Stanton number D) four-fifth power of Nusselt number

In a counter flow heat exchanger, cold fluid enters at 30°C and leaves at 50°C,
whereas the hot fluid enters at 150°C and leaves at 130°C. The mean temperature
difference for this case is

A) 20°C B) 80°C
0) 100°C D) indeterminate

For a completely submerged body with center of gravity ‘G’ and center of buoyancy
‘B’, the condition of stability will be pressure

A) Gis located above B B) G is located below B

C) Gand Bare coincident D) None of the above

Consider the turbulent flow of a fluid through a circular pipe of diameter, D. Identify
the correct pair of statements.

1. Fluid is well mixed

2. Fluid is un mixed

3. Reynolds number less than 2300

4. Reynolds number greater than 2300.

A) 1,4 B) 1,3 C) 2,3 D) 2,4
A flow field which has only convective acceleration is

A) Asteady uniform flow B) An unsteady uniform flow
C) A steady non uniform flow D) All of the above

As per common design practices, the three types of hydraulic turbines in descending
order of flow rates are

A) Pelton, Francis, Kaplan B) Francis, Kaplan, Pelton
C) Pelton, Kaplan, Francis D) Kaplan, Francis, Pelton

A draft tube is not required for a
A) Francis turbine B) Kaplan turbine
C) Pelton wheel turbine D) None of the above

A pitot-static tube measures

Dynamic pressure

Difference in static and dynamic pressure
Static pressure

Atmospheric pressure

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