A man standing 2 m from a charcoal fire is warmed mainly by

When you stand near a charcoal fire, you can feel the warmth of the fire even though the air temperature around you might not have increased significantly. This is because the fire emits electromagnetic waves in the form of heat, which are called thermal radiation. The man is warmed mainly by radiation. The charcoal fire emits thermal radiation that travels in straight lines and does not require a medium to propagate, so it can reach the man without heating up the air in between. Therefore, even if the air temperature around the man remains the same, the thermal radiation emitted by the fire can still warm him up. Convection, on the other hand, is the transfer of heat through a fluid (like air) by the movement of that fluid. In this case, since the man is not in direct contact with the charcoal fire, the heat transfer through convection is minimal. Refraction is the bending of light as it passes through a medium, and has nothing to do with the transfer of heat. Conduction is the transfer of heat through a material or between materials in contact, and is not applicable in this scenario because the man is not in direct contact with the charcoal fire.