Activity Description

This activity makes use of the Bfield physlet. A long, straight, current-carrying wire is oriented perpendicular to the page. A compass is dragged around showing the direction of the magnetic field. A picture showing magnetic field lines draw by a "student" is shown to the students. The students are asked what if anything is wrong with the picture of the magnetic field lines drawn by the "student".

Target Conceptual Difficulty

A compass orients in the direction of the magnetic field with the N pole of the compass pointing in the direction of the Bfield. The magnetic field lines are closed circles in a plane perpendicular to a long straight wire.

PowerPoint

What if Anything is Wrong Task - The Magnetic Field of a Long Straight Wire (TurningPoint)
What if Anything is Wrong Task - The Magnetic Field of a Long Straight Wire (iClicker)

Simulation

What if Anything is Wrong Task - The Magnetic Field of a Long Straight Wire

Presentation Notes

After describing the simulation, the compass is dragged around to various poisitions. The compass needle orients in the direction of the magnetic field. The compass needs to be dragged to enough positions so the students get a good sense of the magnetic field. Once students have answered the clickedr questions, the correct answer is demonstrated by double clicking in the simulation at various points which results in magnetic field lines containing that point to be drawn.

Student Results

The WWT question was administered in a peer instruction format. Prior to group discussion the students answered as follows.

1.) What if anything is wrong with the students diagram?
Responses (percent) (count)
Nothing, the diagram is fine 54.17% 13
The field lines point the wrong way 16.67% 4
The field should look like a bar magnet 25% 6
Some other answer 4.17% 1
Totals 100% 24

Following small group discussion the students answer gave teh following distribution.

2.) What if anything is wrong with the students diagram?
Responses (percent) (count)
Nothing, the diagram is fine 79.17% 19
The field lines point the wrong way 8.33% 2
The field should look like a bar magnet 12.50% 3
Some other answer 0% 0
Totals 100% 24

In this situation Peer Instruction seemed to work well as the number of students correctly identifying that the diagram was correct changed from 54% to 79% following the small group interaction.

Pen and Paper Actvivities

Pen and Paper version of this activty

Follow up tipers from homework assignments, test reviews and test items