A wire is stretched to increase its length by 5% calculate % change in

1.	A wire is stretched to increase its length by 5% calculate % change in its resistance.
Answer» A wire is stretched to increase its length by 5% calculate percentage change in its resistance\xa0Let say Resistance of Wire = RLength = LArea = AResistivity = ρ\xa0R = ρL/A\xa0Volume = V = LA\xa0wire is stretched to increase its length by 5%New L = L + (5/100)L = 1.05LVolume remains sameso new Area = V/1.05L = A/1.05\xa0New resistance = ρ 1.05L /(A/1.05)New R = (ρL/A) * (1.05)²New R = R * 1.05²\xa0increase in R = R * 1.05² - R = R ( 1.05 + 1)(1.05 - 1) = R(2.05)(0.05)\xa0% increase in R = (R(2.05)(0.5)/R ) * 100 = 2.05 * 5 =\xa010.25 %\xa010.25 % increase in resistance

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