If you bend your wire into a current loop the magnetic field lines are still wrapping themselves around the wire (Fig. 1.2a) and you get a magnetic field as shown in Fig. 1.2.b. Adding several current loops together results in a solenoid as shown in Fig. 1.2c. Here the magnetic field is concentrated inside the solenoid and near the ends of the solenoid. As shown on the next page, an electromagnet is not much more than wire wrapped around an iron core.