Question

What is electrical resistivity? In a series electrical circuit comprising of a resistor having a metallic wire, the ammeter reads 5 A. The reading of the ammeter decreases to half when the length of the wire is doubled. Why?

Answer 1

Hello friend your answer is
Electrical resistivity is a fundamental properties that quantifies how strongly a given material opposes the flow of electric current.

Answer 2

Electrical resistivity is the property of the material independent of the geometry of conductor. It is basically resistance for a given area of cross-section of conductor per unit length.

 

When length of wire is doubled, the resistance is also doubled, because resistance is directly proportional to length of wire. Hence according to ohms law for a given potential difference, the current reduces to half.

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