A student notices that a metal vessel on a stove becomes hot, the water inside starts boiling, and the nearby air also becomes warm. Using the concept of heat transfer, explain these observations.
Answer variants:
Convection
Radiation
Convection
Lighter
Radiation
Conduction
Colder
Freezing
Conduction
Flame
Heat particles
Material medium
Convection currents
A metal pan containing water is placed over a flame. Heat from the flame is transferred to the metal pan by . The particles of the metal transfer heat to neighbouring particles through direct contact without moving from their positions.
The water present at the bottom of the pan gets heated first. The heated water becomes and rises upward, while the cooler water sinks downward. This continuous circulation of water forms , which help in distributing heat throughout the water. Thus, the water is mainly heated by .
A person standing near the flame can feel warmth even without touching the pan. This happens because heat from the flame and the hot pan reaches the surroundings through . Unlike conduction and convection, this process does not require a for heat transfer.
As the pan remains on the flame, all three modes of heat transfer work together. Heat spreads through the pan by , water is heated by , and the surroundings are warmed by .