2.what is a transformer? explain how a transformer works including specific details on step up and step down transformers.

A transformer is a device that can be used to step up and step down voltages. This is very useful as by stepping up the voltage, we can reduce power loss along power transmission lines.
Specific details
A transformer is divided into secondary and primary. For a step up transformer, the number of coils in the primary is less than that of secondary. For a step down transformer, the number of turns of primary coil is more than that of secondary.