question_answer

Which factor is immaterial for the wire used in electric fuse?

A)  Length       

B)  Radius

C)  Material      

D)  Current

Correct Answer: A

Solution :

Electric fuse is a type of over current protection device. They are engineered to contribute a negligible amount of extra resistance to the circuits  they protect.  This  is  largely accomplished by making the fuse wire as short as possible. Fuse are primarily rated as current amperes. A fuse wire of  certain material and gauge will blow at a certain current  no matter how long it is. Since, length is not a factor  in current rating the shorter  it can be made the less resistance it will have end to end.