Electromagnetic Fields - 3B SCIENTIFIC PHYSICS U8491790 Instructions D'utilisation

The arrangement behaves like a single bar magnet.
At the free end of the soft iron bar, a pole has
formed with the same polarity as the covered end of
the bar magnet.

5.2 Electromagnetic fields

5.2.1 Straight conductor
•
Scatter iron filings on the box with the straight
conductor so that only the approximate surface
around the vertical current-carrying conductor
passing through the box is covered.
•
Connect up the voltage source.
•
Switch on the power and gently tap the Plexi-
glas box.
•
Immediately switch off the power after the
magnetic field lines have formed.
Ring-shaped field lines form around the conductor.
These become weaker with increasing distance.
Explanation of Fleming's right-hand rule: if the
thumb of your right hand is pointing up in the di-
rection of the current, your fingers point in the
direction of the magnetic field.
5.2.2 Ring-shaped conductor
•
Carry out the experiment described under point
5.2.1 but with the ring-shaped conductor.
•
Demonstrate the magnetic field using the mag-
netic needle.
Ring-shaped magnetic field lines form similar to the
ones with the straight conductor. These lines are
symmetrical to the center of the conductor loop.
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5.2.3 Cylindrical coil (solenoid)
•
A comparison of the magnetic flux lines with those
of the ring-shaped conductor shows that the cur-
rent-carrying cylindrical coil constitutes several
current carrying conductor loops added together.
5.2.4 Electromagnet
•
•
The electromagnet forms magnetic flux lines, which
are most concentrated at the ends of the bar shaped
electromagnet.
Subject to technical amendments
© Copyright 2007 3B Scientific GmbH
Conduct the experiment as described under
point 5.2.1 but this time use the cylindrical coil.
Place a soft iron bar acting as a core into the
cylindrical coil.
Scatter iron filings on the Plexiglas box, switch
on the power and gently tap against the box.
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