Question

The magnetic field at a point 40 mm from a long straight line carrying current of 2A will be ​

Answer 1

Given:

A current carrying wire (2 ampere).

To find:

Magnetic field at 40 mm from wire ?

Calculation:

The general expression of magnetic field due to infinite wire is :

$B = \dfrac{ \mu_{0}(i) }{2\pi r}$

$\implies B = \dfrac{ \mu_{0}(2i) }{4\pi r}$

• $\boxed{\mu_{0}/4\pi}$ value is 10^(-7).

$\implies B = {10}^{ - 7} \times \dfrac{2 \times 2 }{ \frac{40}{1000} }$

$\implies B = {10}^{ - 7} \times \dfrac{4}{ \frac{4}{100} }$

$\implies B = {10}^{ - 7} \times 100$

$\implies B = {10}^{ - 5} \: T$

So, magnetic field intensity is 10^(-5) T or W/m².