A form of circuit protection that contains a metal conductor that melts to open a circuit when current is too high is a __ . circuit breaker ground fault circuit interrupter (GFCI) fuse thermistor fuse

## Step 1<br />The problem is asking us to identify a form of circuit protection that contains a metal conductor that melts to open a circuit when the current is too high. This is a description of a fuse.<br /><br />## Step 2<br />A fuse is a safety device that is designed to melt and break an electrical circuit if the current exceeds a certain level. This is done to prevent overheating or potential fires that could occur due to excessive current.<br /><br />## Step 3<br />The other options provided, such as a circuit breaker, a ground fault circuit interrupter (GFCI), and a fuse thermistor, are also forms of circuit protection, but they operate differently from a fuse.<br /><br />## Step 4<br />A circuit breaker is an automatic electrical switch that disconnects the circuit when it detects an overload or short circuit. It does not contain a metal conductor that melts.<br /><br />## Step 5<br />A ground fault circuit interrupter (GFCI) is a device that shuts off an electric power circuit when it detects that the current is flowing along an unintended path, such as through water or a person. It does not contain a metal conductor that melts.<br /><br />## Step 6<br />A fuse thermistor is a type of resistor that changes its resistance based on temperature. It does not contain a metal conductor that melts.