Why do resistors have a power rating?
Zero ohm resistors usually have a rated current, not a nominal power like most resistors. they are basically a piece of wire. and like all wires, they have a very small typical resistance that will limit the current flowing without excessive heating and possible destruction of the room.
Now the next obvious question is: what are they for?
Another answer suggests that they can be used for configuration jumpers.
They are also sometimes used as jumpers on circuit boards when it is impossible to route a trace without adding another trace layer. the resistors can be installed robotically, while the riders require manual work.
they generally have no percentage tolerance, but a maximum resistance that can be specified, for example 25 milliohms.
They generally share the same substrate as the ohmed resistors of the same surface mount box.
As a result, the maximum power dissipation is the same as that of any resistor in the same enclosure. Since it has the resistance specified above, it will heat up at certain current levels. you will not get very close to low resistance values, but there is still a maximum that you can dissipate.
What is the point of a 0 ohm resistor?
Zero ohm resistors are very common for creating configuration options – essentially jumpers – for optional features, debugging or configuration selection.
That said, they are not perfect (they are not really 0 ohms) and they follow the same manufacturing process as their non-zero counter parts (eg 10 ohms, 33 ohms, etc.). they inherit essentially the same tolerances and nominal powers, which are largely a function of their size. in the end, only a large part of the current / power can be managed by a trace of a given width / thickness.
The same goes for the real resistances of a given type of housing. unless you have superconducting resistors but it would be a totally different situation.
Their tolerance is meaningless because that means that the tolerance of this copper wire is 0.5 mm thick is 5%, and that 0.5 mm thick The tolerance of the copper wire is 1% unless their meaning is 0 ohms or less, so if a resistance of zero ohm has a maximum possible resistance of 1 m ?? (a milliohm) or 0.001 ??, its tolerance would be 0.1%.
What is the preferable tolerance?
Their power is particularly useful for their physical dimensions because they are mainly used as jumpers on printed circuit boards, and the power of a resistor is directly related to its size.
Even though a zero ohm resistor is basically a wire / conductor, its current carrying capacity is still determined by its physical size, and a larger one is needed to connect two larger traces carrying larger currents. it should also be larger to cross, cross or jump a larger space between tracks.
Thus, the power rating would help to place the good size zero resistance in the right place.
