BME Heat Transfer

Question 1

Fourier's law of heat conduction states that heat flux is proportional to:

Accepted Answer

Temperature gradient

Answer

Temperature

Answer

Thermal diffusivity

Answer

Specific heat

Question 2

Which mode of heat transfer does not require a medium?

Accepted Answer

Radiation

Answer

Conduction

Answer

Convection

Answer

Diffusion

Question 3

The Biot number (Bi) in transient heat conduction represents the ratio of:

Accepted Answer

Convective to conductive resistance

Answer

Radiation to convection

Answer

Thermal to viscous forces

Answer

Inertia to viscous forces

Question 4

In a fin, the efficiency is defined as the ratio of actual heat transfer to:

Accepted Answer

Maximum possible heat transfer if the entire fin were at base temperature

Answer

Heat transferred by the base without fin

Answer

Heat transferred by radiation

Answer

Heat stored in the fin

Question 5

What is the thermal resistance for conduction through a flat wall?

Accepted Answer

L/(kA)

Answer

kA/L

Answer

hA

Answer

1/(hA)

Question 6

The Nusselt number (Nu) in convective heat transfer is defined as:

Accepted Answer

hL/k

Answer

VL/ν

Answer

ν/α

Answer

gβΔTL³/ν²