Question

It is hotter for the same distance over the top of the fire than it is by the side is mainly because

• A. air conducts heat upward.
• B. heat is radiated upward.
• C. convection takes more heat upwards.
• D. convection, conduction and radiation all, contribute significantly in transferring heat

Answer 1

The correct option is (C) convection takes more heat upwards.

1. At a point in front of the fire, heat is received significantly due to the process of radiation, while at a point above the fire, heat reaches both due to radiation and convection.
2. The air around the fire gets heat and becomes hotter. As we know that hot air is lighter than cold air and so this hot air moves in the upward direction and cold air comes in the place of the hot air.
3. As hot air continuously moves upward so upward part receives more heat.