Question

A coil of wire of certain radius has 600 turns and a self inductance of 108 mH. The self inductance of a second similar coil of 500 turns will be

• A. 74 mH
• B. 75 mH
• C. 76 mH
• D. 77 mH

Answer 1

Answer: (B)

75 mH

Answer 2

Inductance, L $\propto$ N$^2$ $\therefore$ Inductance of similar coil of different turns is given by L' = L $\frac{N'^2}{N^2} = 108 \times \left( \frac{500}{6000} \right)^2$ = 75 m H