Magnetism - Field LinesThis TACtivity demonstrates the formation of magnetic field lines around magnets

Written By: Divyashree H B

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

This document was generated on 2020-03-26 04:38:43 AM (MST).

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INTRODUCTION

Magnetic field lines are used to represent magnetic fields. They are continuous and form a closedloop without a beginning or an end.

In this TACtivity, we use bar magnets, ring magnets, a cardboard and iron filings to observe themagnetic field lines.

TOOLS:Glue (1)Paper Cutter (1)

PARTS:Cardboard, Thin (1)

A4 SizeGraph sheet (1)

A4 SizeBar Magnet (2)Iron Filings (1)

2 g containerRing Magnet (2)Board Pins (1)Piece of Foam(1cm) (1)

4 cm x 4 cm

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

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— Precautions

Handle paper cutter with care.

— Step 1 - Preparing Cardboard

Take an A4 size cardboard and graph sheet.

Apply glue on one side of the cardboard.

Stick the graph sheet on the glued surface of the cardboard.

— Step 2 - Faces of a Bar Magnet

A bar magnet has three faces, as shown in the figure.

The three faces of the bar magnet are: A - Broad face, B - Narrow face and C - Vertical face.

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

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— Step 3 - Faces of a Ring Magnet

Ring magnet has two faces namely, a flat surface and a curved surface.

— Step 4 - Make the Iron Filing Sprinkler

Take the container with the iron filings.

With the help of a board pin, make holes on the container's lid.

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

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— Step 5 - Bar Magnet Field Lines - Broad Face

Place a single bar magnet under the cardboard, at the centre such that the broad face of themagnet touches the cardboard.

Now, gently sprinkle the iron filings on the graph paper stuck on the cardboard and tap it slowly.

Observe the pattern of the magnetic field lines formed.

— Step 6 - Bar Magnet Field Lines - Narrow Face

Place the single bar magnet under the cardboard, at the centre such that the narrow face of themagnet touches the cardboard.

Now gently sprinkle the iron filings on the surface of the cardboard and tap it slowly.

Observe the pattern of the magnetic field lines formed.

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

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— Step 7 - Bar Magnet Field Lines - Vertical Face

Place the single bar magnet under the cardboard, at the centre such that the vertical face of themagnet touches the cardboard.

Now gently sprinkle the iron filings on the surface of the cardboard and tap it slowly.

Observe the pattern of the magnetic field lines formed.

— Step 8 - Multiple Bar Magnets

Stack two bar magnets such that the broad face touch each other.

Place the set of stacked magnets under the cardboard, at the centre such that the narrow face ofeach of the magnets touch the cardboard.

Now gently sprinkle the iron filings on the surface of the cardboard and tap it slowly.

Observe the pattern of the magnetic field lines formed.

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

This document was generated on 2020-03-26 04:38:43 AM (MST).

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— Step 9 - Ring Magnet Field Lines - Flat Surface

Place a single ring magnet at the centre of the cardboard such that, the flat surface of the magnettouches the cardboard.

Now gently sprinkle the iron filings on the surface of the cardboard and tap it slowly.

Observe the pattern of the magnetic field lines formed.

— Step 10 - Ring Magnet Field Lines - Curved Surface

Insert a ring magnet into a slit, made at the centre of a foam piece, as shown. Place the foam piecewith the magnet under the cardboard such that, the curved surface of the magnet touches thecardboard.

Now gently sprinkle the iron filings on the surface of the cardboard and tap it slowly.

Observe the pattern of the magnetic field lines formed.

Handle paper cutter with care, while making the slit in the foam piece.

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

This document was generated on 2020-03-26 04:38:43 AM (MST).

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— Step 11 - Multiple Ring Magnets

Stack two ring magnets, such that the flat surface of the magnets touch each other.

Insert the stacked magnets into a slit, made at the centre of a foam piece, as shown. Place thefoam piece with the magnets under the cardboard, such that the curved face of the magnets touchthe cardboard.

Now gently sprinkle the iron filings on the surface of the cardboard and tap it slowly.

Observe the pattern of magnetic field lines formed.

Handle paper cutter with care, while making the slit in the foam piece.

— Troubleshooting

Uneven sprinkling - The holes on the container should be of the same size, neither too big nor toosmall.

The field lines are clumsy - Tap the edges of the cardboard sheet gently with the help of yourfingers.

Desired field lines not obtained - Check for the correct orientation of the magnets under thecardboard.

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

This document was generated on 2020-03-26 04:38:43 AM (MST).

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— Suggested Variations

Magnetic field lines in three dimensions.

Magnetic field lines in an electromagnet.

Magnetic field lines between two magnets.

To learn and make the variations for Magnetism - Field Lines, please go to Magnetism - FieldLines (Variations).

Magnetism - Field Lines 2020-03-26[minor]1.2Release:Guide ID: 633 -

This document was generated on 2020-03-26 04:38:43 AM (MST).

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