3B Scientific Air Cushion Plate - Manual (Page 36)

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Physical Experiments on the Air-Cushion Table
2.4. Processes of Electric Conduction
Interpretation:
The motion of electrons in an electric field is ac-
celerated, provided that no other forces act on
the electrons. The acceleration increases with the
intensity of the electric field.
2.4.2 Deflection of an Electron Radiation in
the Electric Field
Components:
Air-cushion table with fan
Overhead projector
Magnetic barrier, short
1 Piece
Electrode 2 Pieces
Manipulating rod 1 Piece
Hover disc, green 2 Pieces
Aluminum hover disc 5 Pieces
High-voltage source
Model simulation
Real Object Model
Vacuum containing Experiment surface of
an electric field the air-cushion table
Electrodes Electrodes
Electrons Aluminum hover discs
How to proceed:
Carefully align the air-cushion table in a hori-
zontal position using the spirit levels. Place the
electrodes onto the experiment surface parallel
to sides nos. 1 and 2, so that the electrode on side
no. 2 rests on its bases, while the bases of the
other electrode point upwards. Position barrier
no. 2 outside of the experiment surface on side
no. 2, running parallel to the electrode on side
no. 2. It is turned by 180° so that the hover discs
cling to it because of the magnetic attraction.
Arrange 2 green hover discs closely to each other
on side no. 3. They are meant to give the alumi-
num disc a certain initial velocity. Feed the di-
rect current of the high-voltage source to the elec-
trodes. Use the manipulating rod to move an alu-
minum disc towards the electrode on side no. 1,
so that is charged. Then move it to the edge of
the experiment surface on side no. 3, between
the two green discs. Turn the fan to a medium
setting and observe the motion of the hover disc.
Repeat the experiment with the other aluminum
discs, varying the distance of the green discs from
the experiment surface.
2.4.1 Motion of an Electron in a Vacuum
Under the Influence of an Electric
Field (Demonstrated By Means of
Mechanical Forces)
Components:
Air-cushion table with fan
Overhead projector
Magnetic barrier, short
1 Piece
Hover disc, orange 1 Piece
Model simulation
Real Object Model
Space containing an Experiment surface of
electric field
the air-cushion table
Strength of the Inclination of the
electric field experiment surface
Electron Hover disc
How to proceed:
Align the air-cushion table horizontally. Attach
magnetic barrier no. 2 in a reversed position with
the number facing downwards, in order to hold
the hover disc. Use the adjusting screw at barrier
no. 2 to lower the experiment surface on that side,
selecting a slight inclination.
Turn the fan to a medium setting. Place the hover
disc on the opposite side of the experiment surface,
holding it with the finger. Then release it and ob-
serve its motion. Repeat the experiment selecting a
stronger inclination of the experiment surface.
Result:
The motion of the hover disc accelerates. The ac-
celeration increases with the degree of inclination.