Which causes an air conditioner to turn on
a.) house temperature decreases cause the bimetallic coil to expand
b.) house temperature decreases cause the bimetallic coil to return to normal
c.)house temperature increases cause the bimetallic coil to expand or contract
d.) house temperature increases cause the bimetallic coil to return to normal

C.)house temperature increases cause the bimetallic coil to expand

Explanation:

A bimetallic strip is used in an air conditioner as a regulator. It is made up of two metals that behaves differently to a change in temperature.

To turn on the air conditoner, the circuit must be complete. When the temperature is high in a room, bimetallic strip responds by expanding and bending to complete the circuit. This puts on the air conditioner and the house begins to cool through exchange of warm and cold air.

When the temperature is too cold, the strip contracts and straightens. This process disconnects the circuit and the air conditioning system ceases to work.

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

l dont know l am s sorry