What affect does temputure has on solid

As the temperature of a solid, liquid or gas increases, the particles move more rapidly. As the temperature falls, the particles slow down. If a liquid is cooled sufficiently, it forms a solid. If a liquid is heated sufficiently, it forms a gas.

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