Q31Short answer
What is electrical resistivity of a material? What is its unit? Describe an experiment to study the factors on which the resistance of conducting wire depends.
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Hint— Resistivity is numerically equal to the resistance of a wire of unit length having an unit area of cross-section. Its unit is ohm metre ( Ω m). Mention the dependence of resistance on length and area of cross section of the wire giving details of experiment using a circuit diagram.