What method does heat transfer?

Which statement is the best example of heat energy transfer by conduction?

• Heat energy is transferred from the surface soil to the rocks below.
• Heat energy is transferred from the bottom to the top of a lake.
• Heat energy is transferred from the Sun to the Earth.
• Heat energy is transferred from the Earth's surface to the upper atmosphere.
  

During which process of energy exchange does cold air displace warmer air?

• absorption
• convection
• radiation
• conduction

What method of energy transfer requires no medium for transfer?

• convection
• conduction
• radiation
• reflection

Thermal energy may be transferred     
 I. in a fluid as a result of density changes of the fluid.  II.  in a non-metallic substance as a result of it touching another object.    
Which of the following correctly identifies each of these energy transfers

• Transfer I: convection
  Transfer II: convection
• Transfer I: convection
  Transfer II: conduction
• Transfer I: radiation
  Transfer II: conduction
• Transfer I: conduction
  Transfer II: convection

 The diagram below shows a room in a house fitted with an electric heater used to heat the  room.
By which processes is the room heated when the heater is in operation?

• convection 
• conduction
• radiation
• reflection

When you use a microwave oven to increase the temperature of a cup of hot chocolate, which type of heat transfer is taking place?

• conduction
• insulation
• radiation
• convection