The mode of heat transfer that occurs when a temperature difference exists in a medium is known asGroup of answer choicesconduction.convection.radiation.none of the above.

The mode of heat transfer that occurs when a temperature difference exists in a medium is known as conduction.

Here's a step-by-step explanation:

1. Heat transfer is the process of thermal energy moving from a higher temperature area to a lower temperature area.

2. There are three modes of heat transfer: conduction, convection, and radiation.

3. Conduction is the process of heat transfer through a solid medium. In this process, the molecules of the medium vibrate about their mean positions and transfer energy to their neighboring molecules.

4. Convection is the process of heat transfer in a fluid (liquid or gas) where the heated fluid rises and the cooler fluid sinks, setting up a circulation pattern of fluid motion.

5. Radiation is the process of heat transfer in the form of electromagnetic waves, and it doesn't require a medium to travel through.

6. In the context of your question, when a temperature difference exists in a medium (like a solid), the mode of heat transfer that occurs is conduction.

The mode of heat transfer that occurs when a temperature difference exists in a medium is known as conduction.

Here's a step-by-step explanation:

1. Heat transfer is the process of thermal energy moving from a higher temperature area to a lower temperature area.

2. There are three modes of heat transfer: conduction, convection, and radiation.

3. Conduction is the process of heat transfer through a solid medium. In this process, the molecules of the medium vibrate about their mean positions and transfer energy to their neighboring molecules.

4. Convection is the process of heat transfer in fluids (liquids and gases) where the heated fluid rises and the cooler fluid sinks due to differences in density, setting up a circulation pattern of fluid motion.

5. Radiation is the process of heat transfer in the form of electromagnetic waves, and it doesn't require a medium to propagate.

6. In the context of your question, when a temperature difference exists in a medium (like a metal rod), heat transfer occurs through conduction. The heat energy is transferred from the higher temperature part of the rod to the lower temperature part through the vibration of molecules.