**Q1: **

A toroid has an inner radius of 20.0 cm and an outer radius of 22.0 cm. The toroid is tightly wound with one layer of 0.250-mm-diameter wire.

How many turns are there on the toroid?

If the current through the toroid windings is 2.0 A, what is the strength of the magnetic field at the center of the toroid?

**Q2: **

A toroid with a square cross section has an inner radius of 25.0 cm. It is wound with 500 turns of wire, and it carries a current of 2.0 A. What is the strength of the magnetic field at the center of the square cross section?

**Q3: **

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 the magnetic susceptibility is , what is the magnetic field within it?

- A T
- B T
- C
- D T
- E T