Project Name: MAGNETIC
FIELD LINES
Name:
CLASS:
SECTION:
SCHOOL:
1
Acknowledgement
Place:
Date:
I would like to express my sincere thanks to Mr/Mrs
________________________________________for his/her valuable
guidance and support in completing my project.
I would also like to express my gratitude towards our principal Mr/Mrs
__________________________for
giving me this great opportunity to do a project
on___________________________________ .
Without their support and suggestions, this project would not have been
completed.
Name:
Signature:
2
Abstract
The magnetic lines of force are lines from the
North to the South poles where the magnetic
field is of equal value. There are, in theory, an
infinite number of them surrounding a magnet,
but in drawings a few only are selected to
represent them, as also happens when iron
filings are used on a paper, they naturally
clump together in lines.
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Linear aligned atoms of a magnetic material
forming a dipole. This results in polarisation of
electrons and they flow in opposite directions.
This ionizes the core as the passage of
electrons are on the surface of the magnetic
material. So the electrons accelerate away from
the core of the magnet. If we place a iron dust
on a paper, the particles will be aligned, clearly
showing the magnetic energy patterns.
Objective
To observe the magnetic field lines around current carrying
conductor.
Theory
1. Magnetic effect of electric current is one of the major effects
of electric current in use, without the applications of which we
cannot have motors in the existing world.
2. A current carrying conductor creates a magnetic field
around it, which can be comprehended by using magnetic lines
of force or magnetic field lines.
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3. The nature of the magnetic field lines around a straight
current carrying conductor is concentric circles with centre at
the axis of the conductor.
4. The strength of the magnetic field created depends on the
current through the conductor.
5. The direction of the magnetic field lines of force around a
conductor is given by the Maxwell’s right hand grip rule or the
right handed corkscrew rule. Imagine that you are holding a
current-carrying straight conductor in your right hand such
that the thumb points towards the direction of current. Then
your fingers will wrap around the conductor in the direction of
the field lines of the magnetic field (See Fig.1). This is known
as right hand thumb rule.
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Materials Required:
A battery (12 V), a variable resistance (or a rheostat),
an ammeter (0–5 A), a plug key, and a long straight
thick copper wire.
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Procedure:
1. Fix the cardboard and insert the wire through the
centre of cardboard such that it is normal to its
plane.
2. Connect the wire with rheostat, ammeter, battery
and plug key in series.
3. Sprinkle the iron filings uniformly on the
cardboard.
4. Keep the variable of the rheostat at a fixed
position and note the current through the ammeter.
5. Close the key and gently tap the cardboard.
6. Observe the pattern of the iron filings over the
cardboard.
Observations:
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1. You will observe that the magnetic field
lines are formed in concentric circles around
the current carrying conductor. These lines
do not intersect each other and are
equidistant from each other.
2. The direction of the field is perpendicular
to the conductor.
3. The magnetic field (B) acting on the object
O increases as the current flowing through it
increases
4. The field increases as object O is closer to
the conductor and decreases as it moves
away from the conductor.
5. The direction of magnetic field lines gets
reversed if the direction of current is
reversed.
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Result:
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o In the above figures, note that there are current
carrying conductors in opposite directions. In both
cases, the current carrying conductor is intercepted
by a cardboard placed at right angles to the current
carrying conductor.
o There are some iron fillings sprinkled on the
conductor.
o When current flows through the conductor, the
iron filing arrange themselves along the magnetic
field.
o We can see that the magnetic field in both cases is
in opposite directions as is the current.
o The magnetic field produced by a current-carrying
straight wire depends inversely on the distance from
it and directly on the current passing through it.
o From this we see that the current carrying
conductor produces a magnetic field around it. The
direction of this magnetic field is given by Right
Hand Thumb Rule.
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References
Books
• Magnetic Effects of Electric Current
• Electricity and Magnetism
• Magnetic Field due to Current - Khan Academ y
