Question

A wire with a resistance R is stretched to 1.5 times its original length, volume remaining constant. The resistance of the wire after it is stretched is about
a) 1.44R
b) 1.56R
c) 2.25 R
d) 2.56 R​

Answer 1

Answer:

c) 2.25 R

Explanation:

$R=\rho \frac{L}{A}\\\\Given \;\;V\;\;is\;\;constant\\\\V=AL\\\\Now \;\;R=\rho \;\frac{L^2}{V}\\\\L=1.5L\\\\R^I=\rho\;(1.5)^2 \frac{L^2}{V}\\\\R^I=2.25 R$

Hope it Helps