Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as_________________?

Related Mcqs:

1. 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

2. 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

3. 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

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. 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

7. 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

8. The friction factor for the turbulent fluid flow in a rough pipe does not depend upon the_________________?

   A. Pipe roughness & pipe diameter
   B. Fluid velocity
   C. Type of flowing fluid
   D. Both B. & C.

9. The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe) ?

   A. A
   B. D
   C. 1/A
   D. 1/A2

10. Nusselt number/Biot number varies___________________?

    A. Inversely with thermal conductivity
    B. Directly with heat transfer co-efficient
    C. Directly with thermal conductivity
    D. Inversely with the dimension of the solid