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) ?

Related Mcqs:

1. In case of water (Prandtl number ≈ 6) flowing over a flat plate heated over the entire length, the thermal boundary layer thickness as compared to hydrodynamic boundary layer thickness is ?

   A. Less
   B. More
   C. Equal
   D. Unpredictable

2. In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness in this case will _______________?

   A. Decrease gradually
   B. Increase gradually
   C. Increase rapidly
   D. Remain constant

3. 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

4. A thin, flat & square plate measuring 2 m × 2 m is freely hanging in ambient air at 25°C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m2. The plate temperature will remain constant at 30°C, if the convective heat transfer co-efficient is ________________ W/m2 °C ?

   A. 50
   B. 100
   C. 150
   D. 200

5. Transition from laminar flow to turbulent flow in fluid flow through a pipe does not depend upon the___________________?

   A. Length of the pipe
   B. Diameter of the pipe
   C. Density of the fluid
   D. Velocity of the fluid

6. 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

7. A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of thermal conductivity 0.14 W/m.K and thickness ______________ metre?

   A. 0.01
   B. 0.1
   C. 0.25
   D. 0.5

8. At the point of boundary layer separation in fluid flow, the _____________________?

   A. Shear stress is maximum
   B. Velocity gradient is flat
   C. Density variation is maximum
   D. Shear stress is zero

9. 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

10. The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be_______________?

    A. Parabolic
    B. Hyperbolic
    C. Straight line
    D. None of these