FREE & FORCED CONVECTION OBJECTIVE QUESTIONS (GATE, IES, IAS)PR...

6. Free & Forced Convection

O

Q

(GATE, IES, IAS)

GATE-1. A coolant fluid at 30°C flows over a heated flat plate maintained at a

constant temperature of 100°C. The boundary layer temperature

distribution at a given location on the plate may be approximated as

T = 30 + 70exp(–y) where y (in m) is the distance normal to the plate and

T is in °C. If thermal conductivity of the fluid is 1.0 W/mK, the local

convective heat transfer coefficient (in W/m

²

K) at that location will be:

[GATE-2009]

(a) 0.2

(b) 1

(c) 5

(d) 10

GATE-2. The properties of mercury at 300 K are: density = 13529 kg/m

³

, specific

heat at constant pressure = 0.1393 kJ/kg-K, dynamic viscosity = 0.1523 ×