The velocity at which the flow changes from laminar flow to turbulent flow is called (A) Critical velocity (B) Velocity of approach (C) Sub-sonic velocity (D) Super-sonic velocity

The velocity at which the flow changes from laminar flow to turbulent flow is called
(A) Critical velocity
(B) Velocity of approach
(C) Sub-sonic velocity
(D) Super-sonic velocity
by

1 Answer

Answer :

Answer: Option A
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Related questions

The velocity corresponding to Reynold number of 2000 is called (A) Sub-sonic velocity (B) Super-sonic velocity (C) Lower critical velocity (D) Higher critical velocity

Description : The velocity corresponding to Reynold number of 2000 is called (A) Sub-sonic velocity (B) Super-sonic velocity (C) Lower critical velocity (D) Higher critical velocity

Last Answer : Answer: Option C

The velocity corresponding to Reynold number of 2800, is called (A) Sub-sonic velocity (B) Super-sonic velocity (C) Lower critical velocity (D) Higher critical velocity

Description : The velocity corresponding to Reynold number of 2800, is called (A) Sub-sonic velocity (B) Super-sonic velocity (C) Lower critical velocity (D) Higher critical velocity

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The velocity at which the laminar flow stops, is known as (A) Velocity of approach (B) Lower critical velocity (C) Higher critical velocity (D) None of these

Description : The velocity at which the laminar flow stops, is known as (A) Velocity of approach (B) Lower critical velocity (C) Higher critical velocity (D) None of these

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When the Mach number is less than unity, the flow is called (A) Sub-sonic flow (B) Sonic flow (C) Super-sonic flow (D) Hyper-sonic flow

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When the Mach number is more than 6, the flow is called (A) Sub-sonic flow (B) Sonic flow (C) Super-sonic flow (D) Hyper-sonic flow

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A flow is called super-sonic if the (A) Velocity of flow is very high (B) Discharge is difficult to measure (C) Mach number is between 1 and 6 (D) None of these

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Pick out the wrong statement. (A) A fluid mass is free from shearing forces, when it is made to rotate with a uniform velocity(B) Newton's law of viscosity is not applicable to the turbulent flow of fluidwith linear velocity distribution(C) Laminar flow of viscous liquids is involved in the lubrication of varioustypes of bearings(D) Rise of water in capillary tubes reduces with the increasing diameter ofcapillary tubes

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Last Answer : A

A flow in which the viscosity of fluid is dominating over the inertia force is called (A) Steady flow (B) Unsteady flow (C) Laminar flow (D) Turbulent flow

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Last Answer : Answer: Option C

General energy equation holds for (A) Steady flow (B) Turbulent flow (C) Laminar flow (D) Non-uniform flow

Description : General energy equation holds for (A) Steady flow (B) Turbulent flow (C) Laminar flow (D) Non-uniform flow

Last Answer : Answer: Option D

A large Reynold number is indication of (A) Smooth and streamline flow (B) Laminar flow (C) Steady flow (D) Highly turbulent flow

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Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of (A) Grashoff number (B) Grashoff number & Reynolds number (C) Reynolds number (D) Grashoff number & Prandtl number

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Last Answer : Option D

A flow is called sub-sonic, if the Mach number is (A) Less than unity (B) Unity (C) Between 1 and 6 (D) More than 6

Description : A flow is called sub-sonic, if the Mach number is (A) Less than unity (B) Unity (C) Between 1 and 6 (D) More than 6

Last Answer : Answer: Option A

When the Mach number is between __________ the flow is called super-sonic flow. (A) 1 and 2.5 (B) 2.5 and 4 (C) 4 and 6 (D) 1 and 6

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In case of a plate and frame filter press, filtrate flow through the cake follows __________ flow. (A) Plug (B) Turbulent (C) Laminar (D) None of these

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Last Answer : (C) Laminar

A straight line is obtained on plotting reciprocal of filtration rate vs. the volume of filtrate for __________ flow of filtrate. (A) Compressible cakes and laminar (B) Incompressible cake and laminar (C) Compressible cake and turbulent (D) Incompressible cake and turbulent

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Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone. (A) Laminar (B) Transition (C) Both 'a' & 'b' (D) Highly turbulent

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Maximum heat transfer rate is achieved in __________ flow. (A) Co-current (B) Counter-current (C) Turbulent (D) Laminar

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The Graetz number is concerned with the (A) Mass transfer between a gas and a liquid (B) Absorption with chemical reaction (C) Heat transfer in turbulent flow (D) Heat transfer in laminar flow

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Maximum heat transfer rate is obtained in __________ flow. (A) Laminar (B) Turbulent (C) Creeping (D) Transition region

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Bernoulli's equation describes the (A) Mechanical energy balance in potential flow (B) Kinetic energy balance in laminar flow (C) Mechanical energy balance in turbulent flow (D) Mechanical energy balance in boundary layer

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Fanning equation is given by (∆P/ρ) = 4f (L/D) (v 2 /2gc ). It is applicable to __________ region flow. (A) Transition (B) Laminar (C) Turbulent (D) Both (B) and (C)

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Last Answer : (D) All (A), (B) & (C)

When the pipe Reynold's number is 6000, the flow is generally (A) Viscous(B) Laminar(C) Turbulent(D) Transition

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Last Answer : (C) Turbulent

In turbulent flow, a rough pipe has the same friction factor as a smooth pipe (A) In the zone of complete turbulence (B) When the roughness projections are much smaller than the thickness of the laminar film (C) Everywhere in the transition zone (D) When the friction factor is independent of the Reynold's number

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Pick out the correct statement. (A) A forced vortex occurs when fluid rotates as a solid about an axis (B) In laminar flow, Newton's law of viscosity does not apply (C) A free vortex occurs, when fluid rotates as a solid (D) In turbulent flow, there are neither cross-currents nor eddies

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Pick out the wrong statement. (A) The form drag is dependent upon the occurrence of a wake (B) The shear stress at any given cross-section of a pipe for steady flow (either laminar or turbulent) varies linearly as the radial distance (C) An ideal fluid is the one, which has negligible surface tension and obeys the Newton's law of viscosity (D) Existence of the boundary layer in fluid flow is because of viscosity of the fluid

Description : Pick out the wrong statement. (A) The form drag is dependent upon the occurrence of a wake (B) The shear stress at any given cross-section of a pipe for steady flow (either laminar or turbulent ... of viscosity (D) Existence of the boundary layer in fluid flow is because of viscosity of the fluid

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f = 16/NRe , is valid for (A) Turbulent flow (B) Laminar flow through an open channel(C) Steady flow(D) None of these

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In turbulent flow, the (A) Fluid particles move in an orderly manner (B) Momentum transfer is on molecular scale only (C) Shear stress is caused more effectively by cohesion than momentum transfer (D) Shear stresses are generally larger than in a similar laminar flow

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The distribution of shear stress in a stream of fluid in a circular tube is(A) Linear with radius for turbulent flow only(B) Linear with radius for laminar flow only(C) Linear with radius for both laminar & turbulent flow(D) Parabolic with radius for both laminar & turbulent flow

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Last Answer : (C) Linear with radius for both laminar & turbulent flow

The laminar boundary layer thickness in zero pressure gradient flow over a flat plate along the x-direction varies as x0.5 while the thickness of turbulent boundary layer varies as (where, x = distance from the leading edge) (A) x1.5 (B) x0.8 (C) x-1.5 (D) x-0.8

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Last Answer : (B) x0.8

Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as (A) Re0.5, Re0.8 (B) Re0.8, Re-0.5 (C) Re0.8, Re0.5 (D) Re-0.8, Re0.5

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Last Answer : (C) Re0.8, Re0.5

Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as (A) Gr0.25, Gr (B) Gr0.25, Gr0.33 (C) Gr, Gr0.25 (D) Gr0.33, Gr0.25

Description : Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as (A) Gr0.25, Gr (B) Gr0.25, Gr0.33 (C) Gr, Gr0.25 (D) Gr0.33, Gr0.25

Last Answer : Option A

Define : (i) Laminar flow (ii) Turbulent flow

Description : Define : (i) Laminar flow (ii) Turbulent flow

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Compare i) Steady and uniform flow ii) Laminar and turbulent flow

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Define laminar flow and turbulent flow.

Description : Define laminar flow and turbulent flow.

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In which type of fluid flow, the velocity of flow of fluid changes from point to point in the fluid at any instant? (A) Rotational (B) Unsteady (C) Turbulent (D) Non-uniform

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Last Answer : (D) Non-uniform

If the depth of water in an open channel is greater than the critical depth, the flow is called (A) Critical flow (B) Turbulent flow (C) Tranquil flow (D) Torrential flow

Description : If the depth of water in an open channel is greater than the critical depth, the flow is called (A) Critical flow (B) Turbulent flow (C) Tranquil flow (D) Torrential flow

Last Answer : Answer: Option C

If the depth of water in an open channel is less than the critical depth, the flow is called (A) Critical flow (B) Turbulent flow (C) Tranquil flow (D) Torrential flow

Description : If the depth of water in an open channel is less than the critical depth, the flow is called (A) Critical flow (B) Turbulent flow (C) Tranquil flow (D) Torrential flow

Last Answer : Answer: Option D

The flow which neglects changes in a transverse direction is known as (A) One dimensional flow (B) Uniform flow (C) Steady flow (D) Turbulent flow

Description : The flow which neglects changes in a transverse direction is known as (A) One dimensional flow (B) Uniform flow (C) Steady flow (D) Turbulent flow

Last Answer : Answer: Option A

The loss of pressure head in case of laminar flow is proportional to (A) Velocity (B) (Velocity)2 (C) (Velocity)3 (D) (Velocity)4

Description : The loss of pressure head in case of laminar flow is proportional to (A) Velocity (B) (Velocity)2 (C) (Velocity)3 (D) (Velocity)4

Last Answer : Answer: Option A

Consider the following statements in respect of steady laminar flow through a circular pipe: 1. Shear stress is zero on the central axis of the pipe 2. Discharge varies directly with the viscosity of the fluid 3. Velocity is maximum at the centre of the pipe. 4. Hydraulic gradient varies as the square of the mean velocity of flow. Which of these statements are correct? (a) 1, 2 , 3 & 4 (b) 1 & 3 only (c) 2 & 4 only (d)3 & 4 only

Description : Consider the following statements in respect of steady laminar flow through a circular pipe: 1. Shear stress is zero on the central axis of the pipe 2. Discharge varies directly with the viscosity of the fluid 3. Velocity is maximum at the ... 2 , 3 & 4 (b) 1 & 3 only (c) 2 & 4 only (d)3 & 4 only

Last Answer : (b) 1 & 3 only

The flow in which the velocity vector is identical in magnitude and direction at every point, for any given instant, is known as (A) One dimensional flow (B) Uniform flow (C) Steady flow (D) Turbulent flow

Description : The flow in which the velocity vector is identical in magnitude and direction at every point, for any given instant, is known as (A) One dimensional flow (B) Uniform flow (C) Steady flow (D) Turbulent flow

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Surging basically implies A. Unsteady, periodic and reversed flow B. Forward motion of air at a speed above sonic velocity C. The surging action due to the blast of air produced in a compressor D. Forward movement of aircraft

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Mach number is defined as the ratio of the local flow velocity to the sonic velocity in the fluid. For what value of Mach number, the gases are considered incompressible? (A) < 0.3 (B) > 3 (C) 50 (D) 1

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Last Answer : (A) < 0.3