AFOQT Practice Test

What is the definition of heat?

1. The process of changing temperature

2. The movement of energy from one substance to another

3. The transfer of energy solely by conduction

4. The ability of a substance to retain energy

The correct answer is: The movement of energy from one substance to another

The correct answer defines heat as the movement of energy from one substance to another, which captures the fundamental concept of how heat operates in thermodynamics. Heat is not merely about temperature change or the ability of a substance to hold energy; rather, it specifically refers to the transfer of thermal energy between bodies or systems due to a temperature difference. In this context, when there is a difference in temperature, energy moves from the hotter substance to the cooler one. This transfer can occur via conduction, convection, or radiation, but the key aspect is that it involves energy being transferred rather than just a change in temperature or energy retention in a single substance. The definition emphasizes the dynamic nature of heat as energy in transit, which is essential for understanding various physical processes, especially in systems involving heat exchange.