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The air near a heat source gets hot and rises. the air from the sides comes in to take its place. This is the way in which the air gets heated by oil heaters. What is this process called?

The air near a heat source gets hot and rises. the air from the sides comes in to take its place. This is the way in which the air gets heated by oil heaters. What is this process called? Correct Answer Convection

Concept:

The movement of energy from one place to another is called energy transfer. Heat transfer mainly takes place due to temperature differences.

There are three modes of Heat transfer.

The fundamental modes of heat transfer are:

Conduction

  • Conduction is the method of transfer of heat within a body or from one body to the other by molecules vibrating at their mean positions.
  • The bodies through which the heat transfers must be in contact with each other. 
  • Conduction occurs usually in solids where molecules in the structure are held together strongly by intermolecular forces of attraction amongst them and so they only vibrate about their mean positions as they receive heat energy and thus pass it to the surrounding molecules through the vibration.

Convection:

  • Convection is the mode of heat transfer which occurs mostly in liquids and gases.
  • In this method, heat transfer takes place through the actual motion of matter from one place within the body to the other.

Radiation

  • Radiation is a form of heat transfer.
  • It does not require any medium and can be used for the transfer of heat in a vacuum as well.
  • This method uses electromagnetic waves which transfer heat from one place to the other. 

Explanation:

  • The air near a heat source gets hot and rises. the air from the sides comes in to take its place.
  • This process is convection. 
  • The hot air is having a lower density.
  • When heated it rises. 
  • After rising, the area remains vacant. 
  • The vacant space is filled by a convection current of air from the cooler area. 

So, the correct option is convection.

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