Physics 電一問

1. a) fuse rating - this is the amount of current when exceeded will bow the fuse.
b) rated voltage - this is the voltage under which the appliance will provide the specified power output.

c) rated current - this is the current which the appliance will consume when operated under the specified voltage.
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2. Why fuse will be broken when there is a sufficient large current
flowing through the fuse?
Fuses are usually made of substances with low melting point. When sufficiently large current is flowing through the fuse, the heat developed by the current is large enough to raise the temperature of the fuse to that above its melting point in a relatively short time, thus melting the fuse instantly.

For The Supplementary,If current flows, since the fuse has resistance so power will be delivered to the fuse. Hence energy dissipated there increase as time pass by. So fuel will be broken if a sufficient time is given. However it is not the real case. Please explain.

The Configuration Of Fuse Is Made Up By The Metal Which In Low-Melting Point.
You May Know That The Heat Of Current Increases Is Proportional To The Current Increases.

So The Large Current Produces A Large Of Heat,If The Heat Higher Than The Capacity Of Fuse,Than The Fuse Will Be Broken.