To measure the magnetic field in a solenoid, a common method involves using a Hall Probe, which measures the magnetic field directly. A standard high school experiment can determine the magnetic field inside a solenoid but may have about a 10% error margin. For a school assignment, it's essential to understand the setup, including the orientation of the Hall bar, which should be aligned correctly with the solenoid's axis. Alternatively, an induction experiment can be designed to measure the induced EMF from a moving solenoid. Understanding these methods will help in accurately measuring the magnetic field.