Electromagnets
Recommended for grades 6–12.
Introduction
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.
Objectives
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 requires each of the following Vernier sensors and equipment (unless otherwise noted):
Additional Requirements
You will also need NXT Sensor Adapter and a LEGO MINDSTORMS NXT robotics system.
Download Experiment Preview
The student-version preview includes:
- Step-by-step instructions for computer-based data collection
- List of materials and equipment
The preview does not include essential teacher information, safety tips, or sample data. We strongly recommend that you purchase the book for classroom use.
Standards Correlations
No standards correlations for this experiment.
Included in the Lab Book
Vernier lab books include a CD with word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.