A magnetic ring has a mean circumference of 20 cm and a cross-section of 20 cm2 and has 800 numbers of turns of wire. When the exciting current is 5 A, the flux is 2 mWb. The relative permeability of iron is nearly
A magnetic ring has a mean circumference of 20 cm and a cross-section of 20 cm2 and has 800 numbers of turns of wire. When the exciting current is 5 A, the flux is 2 mWb. The relative permeability of iron is nearly 39.8