Question

What length of wire of diameter 3 mils will be will be required to construct a coil resistance of 1200 ohms, if the resistivity of the wire is 150 micro-ohm-ft.

Answer 1

hummmmmmmmmmmmmmmmmmmmmmmmmmmmmmm

Answer 2

Note: The radius is $\[3{\rm{m}}\]$ and resistivity is $\[150\Omega /^\circ C\]$

Given,

The diameter of the wire$\[ = 3{\rm{m}}\]$

The resistance of the wire$\[ = 1200\Omega \]$

The resistivity of the wire$\[ = 150\Omega /^\circ C\]$

Solution,

Formula used,the area of the wire$\[ = \pi \frac{{{d^2}}}{4}\]$

Therefore, the length of the wire is

$\[\begin{array}{l} \Rightarrow \frac{R}{\rho }\pi \frac{{{d^2}}}{4}\\ \Rightarrow \frac{{1200}}{{150}} \times \frac{{22}}{7} \times \frac{{3 \times 3}}{4}\\ \Rightarrow 56{\rm{m}}\end{array}\]$

Hence, the length of the wire is $\[56{\rm{m}}{\rm{.}}\]$