4.2.1 electromagnetism

• Any electric current produces a magnetic field
• A solenoid is a loop of wire coiled into a cylindrical shape. The magnetic field lines for a solenoid are drawn below:

  
• inside a solenoid, the field lines are drawn parallel to one another
• the magnetic field decreases in strength as the lines get further from the solenoid
• for solenoids and straight wires, increasing current will increase the strength of the magnetic field. flipping the current will flip the direction of the magnetic field lines