The Magnetic Field in a Coil
Recommended for grades 9–12.
Introduction
When an electric current flows through a wire, a magnetic field is produced around the wire. The magnitude and direction of the field depends on the shape of the wire and the direction and magnitude of the current through the wire. If the wire is wrapped into a loop, the field near the center of the loop is perpendicular to the plane of the loop. When the wire is looped a number of times to form a coil, the magnetic field at the center increases.
In this activity, you will examine how the magnetic field is related to both the number of turns in a coil and the current through the coil. A Magnetic Field Sensor will be used to detect the field at the center of the coil. A complication that must be considered is that the sensor will also detect the Earth’s field and any local fields due to electric currents or some metals in the vicinity of the sensor.
Objectives
- Use a Magnetic Field Sensor to measure the field at the center of a coil.
- Determine the relationship between magnetic field and the number of turns in a coil.
- Determine the relationship between magnetic field and the current in a coil.
- Explore the Earth's magnetic field in your room.
Sensors and Equipment
This experiment requires each of the following Vernier sensors and equipment (unless otherwise noted):
Additional Requirements
You may also need an interface and software for data collection. What do I need for data collection?
Download Experiment Preview
The student-version preview includes:
- Step-by-step instructions for computer-based data collection
- List of materials and equipment
Note: The experiment preview of the computer edition does not include essential teacher information, safety tips, or sample data. Instructions for Logger Pro and other software (such as LabQuest App or TI handheld software, where available) are on the CD that accompanies the book. We strongly recommend that you purchase the book before performing experiments.
Standards Correlations
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.