Rapid Education - Science

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Physics
One Metre
Wheatstone
Bridges
Wheatstone bridges allow accurate
comparison of two resistances
by sliding a ‘jockey’ contact along
a metre length of ‘resistance wire’.
When a balance is achieved,
indicated by a zero reading
on a galvanometer (not included),
the position of the jockey on
the wire, gives an indication
of the ratio of the two fixed
resistances. If the value
of one of the fixed resistances
is known, the value of the
other can be inferred.
These substantial bridges
have broad, heavily plated
brass strips mounted on
a polished hardwood base.
Terminals with 4mm sockets are provided.
24 SWG constantan wire is stretched along the
top of a metre scale graduated in mm and cm.
• Supplied with jockey
• Dimensions 1.13m x 80mm x 5mm approx.
• Available in 2-gap and 4-gap models
• Eisco PH1156 series
Type Order code 1+
Four gap bridge 52-3627 £29.95
Two gap bridge 52-3628 £24.95
565651
Parallel Plate Capacitor
Demonstration
This demonstration capacitor consists of two 120mm circular metal discs mounted
on insulated supports that slide on a track to adjust the distance between them.
The distance can be easily measured by reading their respective positions on the fixed scale.
The apparatus allows students to observe the principle of capacitance, its relationship with charge
and voltage, its dependence on the surface area of conductors and the dielectric medium between two plates.
The apparatus is supplied with three different dielectric materials: glass, cardboard, and Lucite.
• Sturdy extruded aluminium section
• Eisco type PH0879
Electromagnet
The Eisco PH0800A electromagnet consists of
a U-shaped iron core of circular section, with
armature and carrying hook. It is wound with
insulated copper wire and provided with colour-
coded 4mm connectors.
• For use on 4 to 6V DC
• Eisco type PH0800A
Crookes Radiometer
This radiometer consists of a partly evacuated
glass bulb approximately 70mm in diameter,
containing a fine pivot which supports four light
weight metal arms. One side of each vane is
blackened, the reverse side is bright.
On exposure to sunlight, or a sufficiently bright
incandescent light source, the vanes turn. The
absorption of radiant energy by the blackened side
of the vanes sets up a temperature differential with
respect to the bright sides, causing net force to
be exerted by the air molecules on the blackened
side which makes the vanes rotate with their bright
faces leading.
• Approx. 70mm diameter
• Mounted on round plastic moulded base
• Eisco type PH0418A
Demonstration
Meter
Used to demonstrate the working
principle of AC or DC ammeters
or voltmeters, the
meter is housed in a
300 x 150 x 30mm
ABS plastic case
with glass front and
rear panels.
• Moving coil type
• Accuracy of ±
2.5%
• Basic sensitivity
5mA
• 100mV f.s.d. (full
scale deflection)
• Eisco type
PH1116
Demonstration
Dynamo with
Hand Pulley
This working model dynamo is mounted on a 200 x
125mm base plate, which also supports a 125mm
diameter hand-driven pulley. The pulley is coupled,
via a rubber belt, to a smaller pulley on the dynamo
shaft, providing a step-up ratio of rotational speed.
Electrical output is via a pair of 4mm sockets and
a light emitting diode is provided as a simple output
indicator. The model can also be used as a motor
when connected to a 6 to 8V DC supply (not included).
• Electrical output via 4mm terminals
• LED output indicator
• Can be used as a demonstration motor
(requires 6 to 8V DC power supply)
• Includes instruction manual
• Eisco type PH1246
Order code
52-3635
£34.95
Order code
52-3338
£42.95
Order code
52-3443
£24.95
Order code
52-3310
£5.99
Order code
52-3332
£5.95
…where price meets quality