**Q2: **

A long, cylindrical solenoid with 100 turns per centimeter has a radius of 1.5 cm.

Neglecting end effects, what is the self-inductance per unit length of the solenoid?

If the current through the solenoid changes at the rate 5.0 A/s, what is the emf induced per unit length?

**Q3: **

A rectangular toroid with inner radius , outer radius , height , and turns is filled with an iron core of magnetic susceptibility .

What is the self-inductance of the toroid?

If the current through the toroid is 0.5 A, what is the magnetic field at the center of the core?

**Q4: **

A cylindrical solenoid is wrapped around an iron core. The self-inductance of the solenoid is given by where is the solenoid’s length, its cross-sectional area, and is the number of its turns. The solenoid’s core has a magnetic susceptibility of and the current in the solenoid is 2.0 A.

What is the strength of the magnetic field in the core?

What is the effective surface current formed by the atomic current loops in the core?

What is the self-inductance of the solenoid?