Two samples of carbon come into contact. heat will transfer from sample a to sample b if the average kinetic energy of sample a's atoms is the average kinetic energy of sample b's atoms.

Explanation:

When two substances of different temperature are in contact with each other then heat will flow from hot object to cold object until a thermal equilibrium is maintained between them.

Kinetic energy is the energy obtained due to the motion of an object is known as kinetic energy. Total kinetic energy of all the particles present in a system is known as average kinetic energy.

Thus, we can conclude that when two samples of carbon come into contact. Heat will transfer from Sample A to Sample B if the average kinetic energy of Sample A's atoms is greater than the average kinetic energy of Sample B's atoms.

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current