Subtopic: Preservation of food by cooling and freezing
Question Statement:
Plank's equation for predicting food freezing times assumes that:
Options:
(A) All latent heat is removed entirely at a single, fixed freezing temperature, and sensible heat before and after freezing is completely neglected
(B) Freezing occurs over a wide temperature range with variable thermal conductivity
(C) Heat transfer occurs solely by thermal radiation
(D) The food contains zero water
Answer Key:
A
Step-by-Step Solution & Explanation
Plank's equation models freezing as an isothermal phase change occurring strictly at an unvarying initial freezing point ($T_f$), assuming food is initially at $T_f$ and neglecting sensible heat cooling of unfrozen and frozen zones.