Q. The formula, NI = 45000/(L/D), gives proper magnetising current for a coil, regardlessof coil size as long as: (Solved)
1. The test piece is not larger than 1/10 the cross sectional area of the coil
2. AC current only is used
3. The test piece essentially fills the coil
4. The test piece is held tightly against the coil
- a. The test piece is not larger than 1/10 the cross sectional area of the coil