Question

Two fuse wires are rated $5A$ and $20A$. Which of the two is
(i) thicker,
(ii) longer?

Answer 1

i. Comparison of thickness
The current rating of the fuse wire is directly proportional to the thickness of the fuse wire. Higher the thickness of fuse wire, higher will be the current rating.
ii. Comparison of length
Current flowing through a wire does not depend on the length of wire. Hence, rise in temperature of fuse wire is independent of length of wire. Thus, both wires may or may not be of the same length. It cannot be determined with the given information.