How to Calculate the Diameter of a Cylindrical Wire for a Fuse?

Explaining the Calculation of Cylindrical Wire Diameter for a Fuse

A fuse in an electric circuit is a wire that is designed to melt, and thereby open the circuit, if the current exceeds a predetermined value. This is important in preventing damage to electrical components by limiting the current flow. In order to calculate the diameter of a cylindrical wire for a fuse, we need to consider the current density and current passing through the wire.

Current density is defined as the current divided by the cross-sectional area of the wire. By using the formula δ = I/A, where δ is current density, I is current, and A is the cross-sectional area, we can calculate the area of the wire needed to limit the current to a specific value.

Once we have the area of the wire, we can calculate the diameter using the formula A = πd²/4, where d is the diameter of the wire. By rearranging the formula to solve for d, we can determine the diameter of the cylindrical wire required to make a fuse that will limit the current to a certain value.

Using the given values of current density and current, we can substitute them into the equations and calculate the diameter of the cylindrical wire needed for the fuse. In this case, the diameter is determined to be 3.64×10⁻² cm or 3.64×10⁻⁴ m, which will effectively limit the current to 0.46 A.