Question

The inductance of a solenoid 0.5 m long of cross-sectional area 20 cm² and with 500 turns is

• A. 12.5 mH
• B. 1.25 mH
• C. 15.0 mH
• D. 0.12 mH

Answer 1

Answer: (B)

1.25 mH

Answer 2

$L = \frac{\mu_{0}N^{2}A}{l} = \frac{4\pi \times 10^{- 7} \times (500)^{2} \times 20 \times 10^{- 4}}{0.5}$=1.25mH