What is the function of a transformer in residential wiring?

• A. To change the frequency of electricity.
• B. To change the voltage level of electricity.
• C. To store electricity for later use.
• D. To measure the flow of electricity.

Answer: (B)

A transformer serves the crucial role of changing the voltage level of electricity in residential wiring. In typical applications, a transformer can either step up or step down voltage to meet the specific requirements of electrical devices and systems. For instance, residential electrical systems often operate at standard voltages (like 120V or 240V), and a transformer helps to convert higher transmission voltages to these usable levels for home appliances and devices.

Transformers work based on the principles of electromagnetic induction, using coils of wire and magnetic fields to transfer electrical energy from one circuit to another while altering the voltage. This is essential because higher voltage can be transmitted over longer distances more efficiently, but residential appliances require lower voltage for safe operation. Thus, the transformer's ability to modify voltage levels is fundamental to the effective and safe distribution of electrical energy within homes.

The other provided options do not accurately represent the function of a transformer. For instance, changing the frequency of electricity refers to a different type of device known as a frequency converter, while storing electricity is typically performed by batteries or capacitors, not transformers. Measuring the flow of electricity is conducted by ammeters or similar measuring instruments, again separate from the role of a transformer in electrical systems.