HEAT TRANSFER QUIZ

The absorptivity of a grey body at a given temperature __________ with increasing wavelength of radiation.

May increase or decrease ; depends on the material

Increases

Remains constant

Decreases

TRUE ANSWER : ?
YOUR ANSWER : ?

Heat transfer by conduction results due to the transfer of free electrons, kinetic energy & vibrational energy from one molecule to another. Conduction heat transfer can not take place

Between two bodies in physical contact with each other

From one part of a body to the another part of the same body

Between two bodies not in physical contact with each other

Both B & C

TRUE ANSWER : ?
YOUR ANSWER : ?

Rate of heat transfer by vaporisation from pools of water is affected by the

All of these

Viscosity of water

Nature of heating surface and distribution of bubbles

Surface tension of water

TRUE ANSWER : ?
YOUR ANSWER : ?

Viscous & heat sensitive liquids are concentrated in __________ evaporators.

None of these

Long tube

Agitated film

Open pan

TRUE ANSWER : ?
YOUR ANSWER : ?

Correction is applied to LMTD for __________ flow.

Cross

Counter

Parallel

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

What is the steam economy in case of a single effect evaporator system?

< 1

>1

0.1

1

TRUE ANSWER : ?
YOUR ANSWER : ?

Trap is used to remove __________ from steam pipe lines.

Non-condensables

Condensate

Steam

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

The steam ejector is used to

Create vacuum

Superheat the steam

Remove condensate from the steam pipelines

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

The number of kg vaporised per kg of steam fed to the evaporator is defined as

Rate of vaporisation

Economy

Rate of evaporation

Capacity

TRUE ANSWER : ?
YOUR ANSWER : ?

As the difference between the wall temperature and bulk temperature increases, the boiling heat transfer co-efficient

goes through a maximum.

goes through a minimum

continues to increase

continues to decrease

TRUE ANSWER : ?
YOUR ANSWER : ?