Fundamentals of Heat Transfer Quiz 1

The Co-efficient of Thermal conductivity is defined as

• Quantity of heat transfer per unit area per one degree drop in temperature 

•  Quantity of heat transfer per one degree drop in temperature per unit area  

• Quantity of heat transfer per unit time per unit area 

• Quantity of heat transfer per unit time per unit area per one degree temperature drop per unit length 

Specific Speed of Turbine

__________________ has the least value of conductivity

• Air

• Copper

• Aluminium

• Water

Why fins are provided on a heat transfer surface?

• Pressure drop of the fluid should be minimized

• Increase turbulence in flow for enhancing heat transfer

• Surface area is maximum to promote the rate of heat transfer

• Increase temperature gradient so as to enhance heat transfer

Thermal diffusivity of a substance is

• directly proportional to the thermal conductivity

• inversely proportional to density of substance

• inversely proportional to specific heat

• all of the above