**Q1: **

There is a current of 1.5 A through the windings of a large, thin toroid with 200 turns per meter. If the toroid is filled with iron for which magnetic susceptibility , what is the magnetic field within it?

**Q3: **

Suppose you wish to produce a 1.2 tesla magnetic field in a toroid with an iron core for which . The toroid has a mean radius of 25 cm and is wound with 300 turns. What current is required?