Question

Which of the following graph shows the variation of magnetic induction $B$ with distance $r$ from a long current carrying wire is

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

From Biot-Savart law magnetic field due to a long current carrying wire is,

$B=\frac{{\mu }_{0}I}{2\pi r}$

$\Rightarrow B\propto \frac{1}{r}$

When $r\to 0\Rightarrow B\to \infty$ and

$r\to \infty \Rightarrow B\to 0$

Hence it will be rectangular hyperbola.

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, (c) is the correct answer.