Test: Properties of Fluids & Turbulent Flow in Pipes - 1 - Mechanical Engineering MCQ

Assertion (A): In a fluid, the rate of deformation is far more important than the total deformation it self.
Reason (R): A fluid continues to deform so long as the external forces are applied.

What is the unit of dynamic viscosity of a fluid termed 'poise'equivalent to?

The shear stress in turbulent flow is: 

While water passes through a given pipe at mean velocity V the flow isfound to change from laminar to turbulent. If another fluid of specificgravity 0.8 and coefficient of viscosity 20% of that of water, is passed  through the same pipe, the transition of flow from laminar to turbulentis expected if the flow velocity is: 

Flow takes place and Reynolds Number of 1500 in two different pipes with relative roughness of 0.001 and 0.002. The friction factor 

The shear stress developed in lubricating oil, of viscosity 9.81poise, filled between two parallel plates 1 cm apart and moving with relative velocity of 2 m/s is: 

An oil of specific gravity 0.9 has viscosity of 0.28 Strokes at 380C.What will be its viscosity in Ns/m²? 

Assertion (A): In general, viscosity in liquids increases and ingases it decreases with rise in temperature.  Reason (R): Viscosity is caused by inter molecular forces of cohesion and due to transfer of molecular momentum between fluid layers; of which in liquids the former and in gases the later contribute the major part towards viscosity.

If the Relationship between the shear stress ζ and the rate of shear strain  is expressed as then the fluid with exponent n>1 is known as which one of the following?  

Match List-I with List-II and select the correct answer. 

What is the pressure difference between inside and outside of adroplet of water? 
Where 'σ' is the surface tension and’d’ is the diameter of the droplet.

The pressure drop in a 100 mm diameter horizontal pipe is 50 kPa overa length of 10m. The shear stress at the pipe wall is: 

Reynolds stress may be defined as the  

As the transition from laminar to turbulent flow is induced a cross flowpast a circular cylinder, the value of the drag coefficient drops. 

In turbulent flow over an impervious solid wall  

If the surface tension of water-air interface is 0.073 N/m, thegauge pressure inside a rain drop of 1 mm diameter will be:  

A capillary tube is inserted in mercury kept in an open container.Assertion (A): The mercury level inside the tube shall rise above the level of mercury outside.  
Reason (R): The cohesive force between the molecules of mercury is greater than the adhesive force between mercury and glass.