What is the main purpose of a circuit breaker?

The main purpose of a circuit breaker is to protect electrical circuits from overloads and short circuits. Circuit breakers serve as safety devices that automatically interrupt the electrical flow when they detect abnormal conditions that may lead to electrical fires or equipment damage. By breaking the circuit in these situations, they prevent excessive current from passing through the wiring, which could otherwise lead to overheating and potentially cause fires.

This protection is vital for maintaining the safety and reliability of electrical systems. While the other options mention aspects related to electrical systems—such as providing energy to appliances or improving energy efficiency—they do not capture the primary protective role that circuit breakers play in safeguarding electrical installations. Without circuit breakers, electrical systems would be much more vulnerable to dangerous conditions that could result in significant hazards.