Which arrangement strengthens a coil inductor?

Which arrangement strengthens a coil inductor?

• A. Placing additional coils far apart
• B. Placing additional coils close to the existing coil
• C. Using thicker insulation
• D. Reducing turns

Answer: (B)

Inductance grows when the magnetic flux linking a winding increases for a given current. When you add windings right next to the existing coil, the magnetic fields couple strongly between the coils, so the flux produced by one winding links the other more effectively. This mutual coupling adds to the total flux linkage, making the inductance larger than with a single winding. If the coils are placed far apart, the magnetic coupling is weak, so there’s less added flux linkage and the inductance doesn’t increase as much. Using thicker insulation doesn’t change the magnetic path or the number of turns, so it won’t boost inductance. Reducing the number of turns reduces the magnetic field and decreases flux linkage, which lowers inductance.

Inductance grows when the magnetic flux linking a winding increases for a given current. When you add windings right next to the existing coil, the magnetic fields couple strongly between the coils, so the flux produced by one winding links the other more effectively. This mutual coupling adds to the total flux linkage, making the inductance larger than with a single winding.

If the coils are placed far apart, the magnetic coupling is weak, so there’s less added flux linkage and the inductance doesn’t increase as much. Using thicker insulation doesn’t change the magnetic path or the number of turns, so it won’t boost inductance. Reducing the number of turns reduces the magnetic field and decreases flux linkage, which lowers inductance.