Learning Resource Type

Learning Activity

Building a Better Electromagnet

Subject Area

Science

Grade(s)

8

Overview

In this activity, students will construct their own electromagnet from a battery, wire, and a nail.

This resource is a result of the ALEX Resource Development Summit.

    Science (2015) Grade(s): 8

    SC15.8.11

    Plan and carry out investigations to evaluate how various factors (e.g., electric force produced between two charged objects at various positions; magnetic force produced by an electromagnet with varying number of wire turns, varying number or size of dry cells, and varying size of iron core) affect the strength of electric and magnetic forces.

    Unpacked Content

    UP:SC15.8.11

    Vocabulary

    • Investigation
    • Evaluate
    • Factors (e.g., electric force produced between two charged objects at various positions; magnetic force produced by an electromagnet with varying number of wire turns, varying number or size of dry cells, and varying size of iron core)
    • Force
    • Magnetic force
    • Electric force
    • Electromagnetic Force
    • Attraction
    • Repulsion
    • Magnitude
    • Charges
    • Currents
    • Magnetic strength

    Knowledge

    Students know:
    • The strength of electric forces can vary.
    • Cause-and-effect relationships affect the strength of electric forces. These relationships include the magnitude and signs of the electric charges on the interacting objects and distances between the interacting objects.
    • The strength of magnetic forces can vary.
    • Cause-and-effect relationships affect the strength of magnetic forces. These relationships include the magnitude of any electric current present in the interaction, or other factors related to the effect of the electric current (e.g., number of turns of wire in a coil), the distance between the interacting objects, the relative orientation of the interacting objects, and the magnitude of the magnetic strength of the interacting objects.
    • Electric and magnetic forces can be attractive or gravitational.

    Skills

    Students are able to:
    • Identify the phenomena under investigation, which includes objects (which can include particles) interacting through electric and magnetic forces.
    • Identify the purpose of the investigation, which includes which includes objects (which can include particles) interacting through electric and magnetic forces.
    • Develop a plan for the investigation individually or collaboratively.
    • Describe factors used in the investigation including appropriate units (if necessary), independent and dependent variables, controls and number of trials for each experimental condition.
    • Perform the investigation as prescribed by the plan.
    • Use data from the investigation to provide an causal account of the relationship between various factors and the strength of electric and magnetic forces.

    Understanding

    Students understand that:
    • Various factors affect the strength of electric forces.
    • Various factors affect the strength of magnetic forces.

    Scientific and Engineering Practices

    Planning and Carrying out Investigations

    Crosscutting Concepts

    Cause and Effect

    Phase

    Before/Engage
    During/Explore/Explain
    Learning Objectives

    Learning Objectives

    • Students will be able to construct a working electromagnet.

    Activity Details

    1. Students will view the video clip Everyday Uses of Electromagnets.  

    2. Student groups are given a box which contains a piece of 22 gauge wire, a battery, a nail, a battery holder, and several paper clips.  Groups are instructed to use the materials to make an electromagnet that will pick up one or more paper clips. The students then experiment with the materials to find a solution.  If students get stuck, showing them a magnet from inside a speaker helps them realize that they should coil the wire.

    3. When students are successful in their design, they draw and label the parts in Science journal.  

    Assessment Strategies

    Assessment Strategies

    • Student diagrams should show the wire wrapped around the nail and connected to both ends of the battery holder.  All parts should be accurately labeled.

    Variation Tips

    • Students can measure, cut, and strip their own wire.

    Background and Preparation

    Background / Preparation

    • Students should be placed in groups of 4 or fewer.
    • Gather 22 gauge wire, D batteries, battery holders, nails, paper clips, and a speaker that can be taken apart.
    • Pre-cut lengths of 22 gauge wire that will wrap around the iron nails 15-20 times with enough left to attach to the battery holders.

    Digital Tools / Resources

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