Recommended for Middle School through High School.
Electromagnets are formed by winding a coil of wire around an iron core and applying a current to it. A magnetic field forms when current flows through the wire. The strength of the magnetic field is dependent upon the number of wire turns and the strength of the current flow. Electromagnets are used when really strong magnets or precise control are required, such as for moving old cars in a junk yard. Unlike permanent magnets which are made of iron or some other ferromagnetic material, electromagnets are considered “temporary” magnets because stopping the current flow eliminates the magnetic field. Engineers use electromagnets to design motors, televisions, computer disk drives, and music speakers. In this activity, you will build an electromagnet, and use a Magnetic Field Sensor to study the relationship between the number of wire turns and the magnetic field strength of your electromagnet.
In this experiment, you will
Build an electromagnet.
Use a Magnetic Field Sensor and NXT to measure magnetic field strength.
Graph the results.
Determine the relationship between number of wire winds and magnetic field strength.
Sensors and Equipment
This project/activity features the following Vernier sensors and equipment.