Heat Transfer and Change of Phase

A set of flashcards based on key concepts and questions from lecture notes on heat transfer and phase changes.

Role of loose electrons in heat conductors

Loose electrons facilitate the transfer of heat through collisions with neighboring atoms, allowing energy to be conducted.

Effect of air expansion on temperature

When air expands, its temperature decreases due to the decrease in pressure and energy distribution.

Peak frequency of radiant energy and absolute temperature

The peak frequency of radiant energy increases with the absolute temperature of the radiating source, as described by Wien's Displacement Law.

Why the pupil of the eye appears black

The pupil appears black because it absorbs all visible light that enters the eye, not reflecting it.

Rate of cooling of a red-hot poker in different environments

The rate of cooling of a red-hot poker is greater in a cold room compared to a warm oven due to the higher temperature gradient.

Evaporation and its cooling process

Evaporation is the process where liquid turns to gas, absorbing heat from its surroundings and thus causing a cooling effect.

Condensation and its warming process

Condensation is the process where gas turns to liquid, releasing heat to the surroundings, thus acting as a warming process.

Energy exchange when a liquid changes to gas or solid

A liquid absorbs energy when it changes to a gas (evaporation) and releases energy when it changes to a solid (freezing).

Which piece of pie warms quicker in a 100°C oven

A 20°C piece of pie will warm quicker than a 10°C piece of pie in a 100°C oven due to a smaller temperature difference.

Cooking an egg in boiling water on the Moon

No, you could not cook an egg in boiling water on the Moon as the boiling point of water is much lower in a vacuum, thus not providing enough heat.