alleryStart learning →What physical property makes heated air rise during convection?
AHeated air becomes less dense
BHeated air becomes charged
CHeated air becomes more dense
DHeated air loses mass entirely
Answer & Solution
Correct answer: A. Heated air becomes less dense
1. As a fluid's temperature rises, it expands and becomes less dense.
2. Convection is driven by buoyancy, and hot air rises because it is less dense than the surrounding air.
3. Electric charge and mass loss are not part of the described mechanism.
4. Becoming more dense would cause sinking, the opposite of the rising described, so that option is wrong.
5. So reduced density from heating is correct.
_Source: OpenStax Physics (CC BY 4.0), Ch 11 "Thermal Energy, Heat, and Work", section 11.2 Heat, Specific Heat, and Heat Transfer_
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