Question

The average radius of a toroid made out of a nonmagnetic material is $0.1 \, m$ and it has $500$ turns. If it carries $0.5 \, A$ current, then the intensity of the magnetic field along its circular axis in $Tesla$ will be

• A. $2.5\times 10^{- 4}$
• B. $5\times 10^{- 3}$
• C. $5\times 10^{- 2}$
• D. $2\times 10^{- 3}$

Answer 1

Answer: (A)

$N=500$
$R=0.5 \, A$
$r=0.1 \, m$
for toroid
$B=\frac{\mu _{0} N I}{2 \pi r}$
$B=\frac{4 \pi \times 1 0^{- 7} \times 500 \times 0.5}{2 \pi \times \text{0.1}}$
$B\text{ =}\frac{500 \times 5}{1 0^{7}}=2.5\times 10^{- 4}\text{ Tesla}$