Question

A long straight wire carries an electric current of $2A$. The magnetic induction at a perpendicular distance of $5m$ from the wire is :
$({\mu }_0=4\pi \times {10}^{-7}H{m}^{-1})$

• A. $4\times {10}^{-8}T$
• B. $8\times {10}^{-8}T$
• C. $12\times {10}^{-8}T$
• D. $16\times {10}^{-8}T$

Answer 1

Answer: (B)

$8\times {10}^{-8}T$

Here,

$i=2A$

${\mu }_o=4\pi \times {10}^{-7}H{m}^{-1}$

$r=5m$

Magnetic induction due to long straight wire at a perpendicular distance is given by,

$B=\frac{{\mu }_{o}i}{2\pi r}$

putting the given values we get,

$B=\frac{4\pi \times {10}^{-7}\times 2}{2\pi \times 5}$

$\therefore B=8\times {10}^{-8}T$