A current of 4 mA in a coil of self-inductance 10 mH and 200 turns produces total flux:
- $8 \times 10^{-3}$ Wb total
- $4 \times 10^{-5}$ Wb total (i.e. $2 \times 10^{-7}$ Wb per turn)
- $2 \times 10^{-5}$ Wb total
- $2 \times 10^{-7}$ Wb per turn
Show answer and solution
Correct answer: B. $4 \times 10^{-5}$ Wb total (i.e. $2 \times 10^{-7}$ Wb per turn)
**Total flux linkage:** $\phi = L i = (10 \times 10^{-3}) \times (4 \times 10^{-3}) = 4 \times 10^{-5}$ Wb.
Flux per turn = $\phi/N = (4 \times 10^{-5})/200 = 2 \times 10^{-7}$ Wb.