# Question #1a79d

May 20, 2017

See below

#### Explanation:

Current is Simply the rate of flow of charge per unit time , nut if we are talking about electromagnetic current here we come across the strange behavior of current . which states when ever charge flows in closed loops it creates magnetic field .
You think correct about the ferromagnetic and its effects.

It plot the graph we must find a relation between them which is given by BiotSarvat law which states that magnetic field B due to current carrying wire at certain distance r from it about its length dl has relation
$I$=current
$\mathrm{dl}$=length of piece of wire
${r}^{2}$ = perpendicular distance from wire

$\mathrm{dB} \propto I$
$\mathrm{dB} \propto \mathrm{dl}$
$\mathrm{dB} \propto \frac{1}{r} ^ 2$

so we can combine it to form

$\mathrm{dB} \propto \frac{I \cdot \mathrm{dl}}{r} ^ 2$

$\mathrm{dB} = {\mu}_{o} / \left(4 \pi\right) \cdot \frac{I \cdot \mathrm{dl}}{r} ^ 2$

where ${\mu}_{o} / \left(4 \pi\right)$ is a constant
$\therefore$ now we know from above law that $\mathrm{dB} \propto I$ graph{x=y [-10, 10, -5, 5]}

which gives linear graph hence your point is proved