Question

The variation of applied potential and current flowing through a given wire is shown in figure. The length of wire is $31.4cm$. The diameter of wire is measured as $2.4cm$. The resistivity of the given wire is measured as $x\times 10^{-3}\Omega cm$. The value of $x$ is _____. [Take $\pi =3.14]$

Answer 1

Answer: 144

$1=\rho \frac{\ell }{A}$
$1=\frac{\rho \times 31.4}{\frac{\pi (2.4{)}^2}{4}}$
$\frac{\pi (2.4{)}^2}{4}=\rho \times 314$
$\frac{2.4\times 2.4}{4}=\rho \times 10$
$\frac{0.6\times 2.4}{10}=\rho$
$\frac{1.44}{10}=\rho$
$0.144=\rho$
$144\times 10^{-3}=\rho$