HEAT TRANSFER QUIZ

The equation, (NSt x N2/3Pr) = f/2, is the __________ analogy.

Colburn

Reynolds

Prandtl

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

Baffle spacing

Should be less than the inside diameter of the shell

None of these

Should be less than one fifth the diameter of the shell

Is not the same as baffle pitch

TRUE ANSWER : ?
YOUR ANSWER : ?

A concentric double pipe heat exchanger as compared to the shell and tube heat exchanger for the same heat load requires

More space

None of these

Lower maintenance cost

Less heating surface

TRUE ANSWER : ?
YOUR ANSWER : ?

In forced convection, the Nusselt number is a function of

Re and Sc

Re and Pr

Re and Gr

Pr and Gr

TRUE ANSWER : ?
YOUR ANSWER : ?

Air is best heated with steam in a heat exchanger of

shell and tube type

double pipe type with fin on steam side

double pipe type with fin on air side

plate type

TRUE ANSWER : ?
YOUR ANSWER : ?

A dephlegmator is a

Partial condenser

Double pipe heat exchanger

Total condenser

Vacuum evaporator

TRUE ANSWER : ?
YOUR ANSWER : ?

What is the emissivity of a black body?

1

0.9

0.5

TRUE ANSWER : ?
YOUR ANSWER : ?

The heat transfer co-efficient in film type condensation is __________ that for dropwise condensation.

Greater than

Lower than

Is same as

Half

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following has the lowest overall heat transfer co-efficient?

Molten sodium

Water

Dowtherm

Air

TRUE ANSWER : ?
YOUR ANSWER : ?

Nusselt number for full developed, laminar, constant property flow in a pipe at uniform heat flux is

18

83

0.72

4.364

TRUE ANSWER : ?
YOUR ANSWER : ?

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