A 14.0-m length of wire consists of 9.0 m of copper followed by 5.0 m of aluminum, both of diameter 1.2 mm . A voltage difference of 85 mV is placed across the composite wire. The resistivity of copper is 1.68×10−8Ω⋅m and the resistivity of aluminum is 2.65×10−8Ω⋅m.

when the use of electricity burdens the fuse and miniarure circuit beakers and there is a possibility of a fuse then they automatically cut off the electricity supply to your homes and after you fix the problem u jzt switch it on and it continues the supply of electricity to ur homes