Question

How do you measure a fuse inside a circuit

Answer 1

To measure a fuse, you can visually inspect it or test it with a multimeter for continuity. Remove the fuse from the circuit and ensure power is off before measurement to avoid shock.

Step-by-step explanation:

To measure a fuse inside a circuit, one typically needs to remove the fuse from its holder and examine it visually to see if the wire within the fuse is intact. If the wire has melted or appears broken, the fuse has been 'blown' and needs to be replaced. However, if you want to test if a fuse is working without removing it, you can use a multimeter to check for continuity. If the multimeter shows continuity, the fuse is still good; if there's no continuity, the fuse has blown. It is essential to make sure that the power is turned off before attempting to measure a fuse in a live circuit to avoid electric shock. Furthermore, you should never attempt to bypass a fuse or replace it with one of a higher rating, as this could cause a fire or damage the electrical system.

Answer 2

To measure a fuse, an ammeter is connected in series with the circuit, allowing measurement of the current without significantly altering the circuit's resistance. Ammeters measure the flow of charge in amperes. Summing currents of multiple devices can indicate whether a fuse's rated current will be exceeded.

Step-by-step explanation:

To measure a fuse inside a circuit, we need to understand how a fuse operates. A fuse consists of a wire with a low melting point that is designed to heat up and melt (or blow) when the current passing through it exceeds a specified rating, so as to protect the rest of the circuit from too high currents. The current capacity of a fuse is measured in amperes (amps), and it is important to match the fuse rating with the current requirements of the circuit it protects.

To measure the current through the fuse, an ammeter must be used. This device measures the flow of charge, and one ampere (1 A) is equivalent to one coulomb of charge passing a point in the circuit per second (1 C/s). The ammeter is connected in series with the fuse so as to not alter the circuit's resistance substantially, as it has a very low intrinsic resistance. Moreover, ammeters often contain a protective fuse to shield the meter itself from excessive currents.

When analyzing a circuit with multiple devices plugged into the same outlet, such as an 1800-W toaster, a 1400-W speaker, and a 75-W lamp in a circuit with a 15-A fuse, the individual current drawn by each device can be calculated and summed to determine whether the cumulative current will exceed the fuse's rating. This calculation is crucial to prevent circuit damage due to overcurrent.