Question

The current in straight wire if the magnetic field
$10^{-6}W{m}^{-2}$ produced at 0.02 m away from it is

• A. 0.1 A
• B. 1 A
• C. zero
• D. 10 A

Answer 1

Answer: (A)

In case of straight conductor of infinite length, the magnetic
field is given by
$B=\frac{{\mu }_0}{4\pi }\times \frac{2i}{a}$
$\Rightarrow 10^{-6}=\frac{10^{-7}\times 2\times i}{0.02}$
$\Rightarrow i=0.1A$