Question

If the self inductance of 500 turns coil is 125 mH, then the self inductance of the similar coil of 800 turns is

• A. 48.8 mH
• B. 200 mH
• C. 290 mH
• D. 320 mH

Answer 1

Answer: (D)

320 mH

Answer 2

as $\frac{L_{1}}{L_{2}} = \frac{N_{1}^{2}}{N_{2}^{2}}$

Here self inductance of 500 turns coil = 125 mH

$\therefore$ L for the coil of 800 turns $= \frac{125}{(500)^{2}} \times (800)^{2}$

$= 320mH$