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. $\frac { 1 } { 4 \pi } \mu _ { 0 } W b$
• B. $\frac { 1 } { 2 \pi }$ μ₀Wb
• C. $\frac { 1 } { 3 \pi } \mu _ { 0 } W b$
• D. $0.4 \mu _ { 0 } W b$

Answer 1

Answer: (A)

$\frac { 1 } { 4 \pi } \mu _ { 0 } W b$

Answer 2

$N \phi = L i \Rightarrow \phi = \frac { L i } { N } = \frac { 8 \times 10 ^ { - 3 } \times 5 \times 10 ^ { - 3 } } { 400 } = 10 ^ { - 7 } = \frac { \mu _ { 0 } } { 4 \pi } w b$