Question

What is electrical resistivity ? Derive its SI unit. In a series electrical circuit comprising a resistor made up of a metallic wire, the ammeter reads 100 mA. If the length of the wire is doubled, how will the current in the circuit change? Justify your answer.

Answer 1

Dear Student,
1)Electrical resistivity is a fundamental property of a material that quantifies how strongly that material opposes the flow of electric current. A low resistivity indicates a material that readily allows the flow of electric current. Resistivity is commonly represented by the Greek letter ρ.2)A low resistivity indicates a material that readily allows the flow of electriccurrent. Resistivity is commonly represented by the Greek letter ρ (rho).The SI unit of electrical resistivity isthe ohm-metre (Ω⋅m).3)In a series electrical circuit comprising a resistor made up of a metallic wire, the ammeter reads 100mA. The reading of the ammeter decreases to half when the length of the wire is doubled. ... Hence according to ohms law for a given potential difference, the current reduces to half.

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