Test: Properties of Fluids & Turbulent Flow in Pipes - 2 - Mechanical Engineering MCQ

Newton’s law of viscosity depends upon the 

Consider the following statements: 
1. The friction factor in laminar flow through pipes is independent of roughness.
2. The friction factor for laminar flow through pipes is directlyproportional to Reynolds number.
3. In fully turbulent flow, through pipes, friction factor is independentof Reynolds number.Which of the statements given above are correct?

In a fully turbulent flow through a rough pipe, the friction factor 'f' is(Re is the Reynolds number and ξ_S / D is relative roughness)  

What are the dimensions of kinematic viscosity of a fluid? 

Decrease in temperature, in general, results in 

Match List-I (Type of fluid) with List-II (Variation of shear stress) and select the correct answer: 

Assertion (A): Blood is a Newtonian fluid. Reason (R): The rate of strain varies non-linearly with shearstress for blood.

In an experiment, the following shear stress - time rate of shearstrain values are obtained for a fluid: 
Time rate of shear strain (1/s):       0     2       3     4
Shear stress (kPa):                        0    1.4    2.6   4

Surface tension is due to  

What is the pressure inside a soap bubble, over the atmospheric pressure if its diameter is 2 cm and the surface tension is 0·1N/m? 

Which one of the following is correct? The capillary rise on depression in a small diameter tube is

Assertion (A): A narrow glass tube when immersed into mercurycauses capillary depression, and when immersed into watercauses capillary rise. 
Reason (R): Mercury is denser than water.

The capillary rise at 20⁰C in clean glass tube of 1 mm diameter containing water is approximately 

In a turbulent flow, are time average velocity components.The fluctuating components are u', v' and w’ respectively. Theturbulence is said to be isotropic if:  

If for a turbulent flow then it signifies that  

When we consider the momentum exchange between two adjacent layers in a turbulent flow, can it be postulated that if at an instantthere is an increase in u' in the x-direction it will be followed by achange in v' in the y direction?

In fully-developed turbulent pipe flow, assuming 1/7^th power law, the ratio of time mean velocity at the centre of the pipe to that averagev elocity of the flow is:  

A U-tube is made up of two capillaries of diameters 1.0 mm and 1.5 mm respectively. The U tube is kept vertically and partially filled with water of surface tension 0.0075kg/m and zero contact angles.
Calculate the difference in the level of the menisci caused by the capillarity.

A metal plate 1.25 m × 1.25 m × 6 mm thick and weighting 90 N is placed midway in the 24 mm gap between the two vertical plane surfaces. The Gap is filled with an oil of specific gravity 0.85 and dynamic viscosity 3.0N.s/m². Determine the force required to lift the plate with a constant velocity of 0.15 m/s.

In order to form a stream of bubbles, air is introduced through a nozzle into a tank of water at 20°C. If the process requires 3.0 mm diameter bubbles to be formed, by how much the air pressure at the nozzle must exceed that of the surrounding water? What would be the absolute pressure inside the bubble if the surrounding water is at 100.3 kN/m²? (σ = 0.0735 N/m)

The volumetric change of the fluid caused by a resistance is known as

A 400 mm diameter shaft is rotating at 200 rpm in a bearing of length 120 mm. If the thickness of oil film is 1.5 mm and the dynamic viscosity of the oil is 0.7 Ns/m² determine:
(i) Torque required overcoming friction in bearing;
(ii) Power utilization in overcoming viscous resistance;

Match List-I (Physical properties of fluid) with List-II (Dimensions/Definitions) and select the correct answer:  

Fluids that require a gradually increasing shear stress to maintain a constant strain rate are known as

Consider the following statements:  
1. Gases are considered incompressible when Mach number isless than 0.2
2. A Newtonian fluid is incompressible and non-viscous
3. An ideal fluid has negligible surface tension
Which of these statements is /are correct?

At the interface of a liquid and gas at rest, the pressure is:  

Which one of the following sets of conditions clearly apply to anideal fluid?