What is the role of a circuit breaker?

The role of a circuit breaker is primarily to open and close the circuit automatically during fault conditions. In an electrical system, circuit breakers are crucial safety devices that protect circuits from overloads and short circuits. When there is an abnormal condition, such as excessive current flow that poses a risk to equipment or personnel, the circuit breaker detects this fault and interrupts the current flow to prevent damage. This automatic opening and closing mechanism helps ensure that the electrical system operates safely and effectively.

The other answer choices represent functions that are not related to the primary purpose of a circuit breaker. Converting electrical energy into mechanical energy pertains to devices like motors, while storing electrical energy for later use is the function of capacitors or batteries. Amplifying electrical signals is the role of devices like operational amplifiers in electronic circuits. These differences clarify why the selected answer accurately defines the function of a circuit breaker.