Question

The inductance of a closed-packed coil of $400$ turns is $8\, mH$. A current of $5\, mA$ is passed through it. The magnetic flux through each turn of the coil is

• A. $\frac{1}{4 \pi} \mu_{0} Wb$
• B. $\frac{1}{2 \pi} \mu_{0} Wb$
• C. $\frac{1}{3 \pi} \mu_{0} Wb$
• D. $0.4 \mu_{0} Wb$

Answer 1

Answer: (A)

$N \phi =L i \Rightarrow \phi$
$=\frac{L i}{N}=\frac{8 \times 10^{-3} \times 5 \times 10^{-3}}{400}$
$=10^{-7}=\frac{\mu_{0}}{4 \pi} Wb$