Answer: the difference in the number of turns in each coil
Explanation:
A transformer is a device which is used transfer electrical energy from one circuit to another. It uses coils - primary and secondary having different turns. The current passes through the primary coil which induces emf in the secondary coil. The increase in potential depends on the number of turns in the coil.
[tex]\frac{V_{out}}{V_{in}}=\frac{N_s}{N_p}[/tex]
where V is the voltage and N is the number of turns.
