Heat transfer

Question 1

Modes of heat transfer

Answer 1

1. Conduction
2. Convection
3. Radiation

Question 2

Conduction

Answer 2

Mode of heat transfer whereby heat is transferred in solids

Question 3

Convection

Answer 3

the process by which heat is transferred in fluids

Question 4

Radiation

Answer 4

Form of heat transfer that takes place through a vacuum.

Question 5

Thermal expansion

Answer 5

• The tendency of matter to change in shape, volume and area in response to a change in temperature.
• Some substances expand when heated due to the increased kinetic energy of
  the atoms

Question 6

Linear Expansivity

Answer 6

fractional change in length per unit change in kelvin temperature

Question 7

Why is pyrex chosen to envelope the X-ray tube

Answer 7

its linear expansivity is very similar to that
of copper anode so that both expand by the same amounts

Question 8

evaporation

Answer 8

the process that changes liquid water to gaseous water.

Question 9

What is vaporization?

Answer 9

Vaporization is the conversion of a substance from the liquid or solid phase into the gaseous (vapor) phase.

Question 10

How does vaporization occur in the context of an X-ray tube?

Answer 10

Vaporization occurs from both the filament and anode of the X-ray tube since both are subjected to very high temperatures.