law. Using Ohm's law define the resistance of a conductor. (ii) What is resistivity conductor? Which is more fundamental, the resistance or the resistivity? Explain . (iii) A cogent of2A flows through a wire of length 314.2 m and diameter of 2 mm and resistivity of
4.S *104 Qm. Find the resistance and the voltage across the two ends of the wire. (04
: (i) Ohm's Law
If a conductor is kept at a constant temperature, the current flowing through it is directly proportional to the potential difference between its ends.
Resistance of a conductor (defined by using Ohm 's Law)
If a conductor is kept at a constant temperature , the ratio of the pctential difference between the two ends of the conductor to the current flowing through that conductor is the resistance of the conductor. (ii) Resistivity
The resistivity of a conductor is the resistance of a conductor having one unit c sectional area and one unit length,
,etor Resistivity is more fundamental than resistance. While the resistance of a cc ofthe conductor the resistivity of a conductor is a constarJantity depends on the dimensions independent ofthe conductor 's dimensions.
