Wow, that are a lot of questions!
Perhaps, this one graph can answer them all
Basically, its time versus current.
If you have a 1A fuse, will it carry 1A forever?
forever is quite a long time
I would say not forever, but very long.
How about 1.1A? How long would it take 2A to blow the fuse? 5A? 10A?
A bit shorter then forever, but still very long. Depending on construction of the fuse, size, filling and ambient temperature.
How long would it take 2A to blow the fuse? 5A? 10A?
Have a look at the graph for those:
A 5A BS3036 fuse can withstand 13A for 5 seconds.
Important again is the construction of the fuse, size, filling and ambient temperature and all other stuff that I forgot.