How to Calculate the Diameter of a Blown Fuse Wire

What is the diameter of the wire in the fuse?

A certain fuse "blows" if the current in it exceeds 1.0 A, at which instant the fuse melts with a current density of 600 A/cm^2. What is the diameter of the wire in the fuse?

Answer:

The diameter of the wire in the fuse is approximately 0.0316 cm or 0.316 mm.

To find the diameter of the wire in the fuse, we can use the formula for current density: J = I / (pi * r^2) where J is the current density, I is the current, and r is the radius of the wire. We know that the current density when the fuse blows is 600 A/cm^2 and the maximum current is 1.0 A.

So we can rearrange the formula and solve for r: r = sqrt(I / (pi * J)). Substituting the values, we get: r = sqrt(1.0 A / (pi * 600 A/cm^2)) = 0.005 cm.

Finally, we can convert the radius to diameter by multiplying by 2: diameter = 2 * r = 0.010 cm = 0.0316 cm or 0.316 mm (approx.).

By using the given data and the formula for current density, we were able to calculate the diameter of the wire in the blown fuse. Understanding these calculations can help in determining the necessary dimensions for different electrical components.