A copper wire of conductance 72 Ω-1 is melted and redrawn to thrice its original length. Find the Conductance of stretched wire.
As we learnt
Since volume of the wire does not change.
Þ l1A1 = l2 A2 where l1 and A1 are the initial length and cross-section of the wire, and l2 and A2 are the final length and cross-section.
C1 = A1/ρL1 and C2 = A2/ ρ L1
Þ C1/C2 = L22/L21 = 9
Þ C2= C1/9 = 8 Ω-1
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