1
MCQ (Single Correct Answer)

### GATE ME 2003

Consider a laminar boundary layer over a heated flat plate. The free stream velocity is ${U_\infty }.$ At some distance $x$ from the leading edge the velocity boundary layer thickness is ${\delta _v}$ and the thermal boundary layer is ${\delta _r}.$ If the Prandtl number is greater than $1,$ then
A
${\delta _v} > {\delta _r}$
B
${\delta _r} > {\delta _v}$
C
${\delta _v} = {\delta _r} \sim \left( {{U_\infty }} \right)$
D
${\delta _v} = {\delta _r} \sim {x^{ - 1/2}}$
2
MCQ (Single Correct Answer)

### GATE ME 2002

The properties of mercury at $300K$ are : density $= 13529kg/{m^3},$ ${C_P} = 0.1393$ $kJ/kgK,$ dynimic viscosity $= 0.1523\,\, \times \,\,{10^{ - 2}}\,\,N - s/{m^2}$ and thermal conductivity $=8.540$ $W/m$-$K$. The Prandtl number of the mercury at $300K$ is
A
$0.0248$
B
$2.48$
C
$24.8$
D
$248$
3
MCQ (Single Correct Answer)

### GATE ME 2001

Water (Prandtl number $=6$ ) flows over a flat plate which is heated over the entire length. Which one of the following relationship between the hydrodynamic boundary layer thickness $\left( \delta \right)$ and thermal boundary layer thickness $\left( {{\delta _t}} \right)$ is true
A
${\delta _t} = \delta$
B
${\delta _t} < \delta$
C
${\delta _t} > \delta$
D
can not be predicted
4
Subjective

### GATE ME 1996

Match List - ${\rm I}$ with List - ${\rm II}$ and select the correct answer using the code given below the Lists:

List - ${\rm I}$
$A.$ Grashof number
$B.$ Schmid number
$C.$ Weber number
$D.$ Fourier number

List - ${\rm II}$
$1.$ Mass diffusion
$2.$ Transient heat conduction
$3.$ Free convection
$4.$ Forced convection
$5.$ Surface tension
$6.$ Radiation

## Answer

$A - 3,\,\,B - 1,\,\,C - 5,\,\,D - 2$

### EXAM MAP

#### Graduate Aptitude Test in Engineering

GATE ECE GATE CSE GATE CE GATE EE GATE ME GATE PI GATE IN

#### Joint Entrance Examination

JEE Main JEE Advanced