Question

The magnetic induction in air at a point $1cm$ away from a long wire that carries a current of $1A$, will be

• A. $1\times {10}^{-5}T$
• B. $2\times {10}^{-5}T$
• C. $3\times {10}^{-5}T$
• D. $4\times {10}^{-5}T$

Answer 1

Answer: (B)

$2\times {10}^{-5}T$

$B=\frac{{\mu }_0}{4\pi }\times \frac{2i}{r}={10}^{-7}\times \frac{2\times 1}{{10}^{-2}}=2\times {10}^{-5}Tesla$