What role does a transformer play in electrical systems?

• A. It converts direct current to alternating current
• B. It changes the voltage level of alternating current for power transmission
• C. It stores electrical energy for future use
• D. It generates electricity from renewable sources

Answer: (B)

A transformer plays a critical role in electrical systems by changing the voltage level of alternating current (AC) for power transmission. This is essential because electrical power can be transmitted more efficiently at high voltages, which reduces energy losses that occur due to resistance in the wires. By stepping up the voltage for transmission over long distances, less current is needed, which minimizes I²R losses, where I is the current and R is the resistance.

When the power reaches its destination, transformers can then step down the voltage to a safe and usable level for residential or commercial use. This adjustment ensures that electrical devices can operate safely and effectively without risking damage from high voltages.

It’s worth noting that the other options do not describe the function of a transformer. Transforming direct current (DC) to alternating current is not a transformer’s role; that function is typically carried out by an inverter. Storing electrical energy is a task performed by batteries or capacitors, not transformers. Generating electricity from renewable sources involves methods such as solar panels or wind turbines, rather than the function of voltage transformation attributed to a transformer.