Q6 of 30 Page 127

A negligibly small current is passed through a wire of length 15 m and uniform cross-section 6.0 × 10–7 m2, and its resistance is measured to be 5.0 W. What is the resistivity of the material at the temperature of the experiment?

Given, the length of wire l = 15 metre

Area of cross section of wire a = 6.0 × 10-7 metre square


Resistance of material of wire, R = 5 Ω


Resistivity of material of wire = ρ






Hence Resistivity of material of wire is 2 × 10-7 metre


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