3B Scientific Coil with Variable Number of Turns per Unit Length - Manual

3B SCIENTIFIC® PHYSICS
1
Coil with Variable Number of Turns per Unit Length
1000965
Instruction Sheet
07/12 ALF
1 Scale
2 4mm safety sockets
3 Coil wire
4 Coil bobbin
1. Safety instructions
• Operation of the coil is only allowed with
extra low voltages.
• Do not exceed the maximum current for
long-term use.
• Do not touch the coil during the experiment.
• If the coil should become overloaded, they
must be allowed to cool before switching on
the current again.
• Any modifications to the set-up must be
made with the primary voltage switched off.
2. Description
The coil of variable number of turns per unit
length is used to investigate the magnetic flux
density in cylindrical coils as a function of the
number of turns per unit length.
The coil has a cylindrical bobbin made from
acrylic glass with adjustable 4 mm safety sock-
ets. By means of a clamping device the distance
between the ends of the coil windings can be
mechanically locked. A cm scale allows easy
reading of the coil length. The current may ex-
ceed the indicated long-term maximum for short
periods.
3. Technical data
Coil diameter: 100 mm
Number of turns: 30
Coil length: 490 mm
Max. Current: 10 A, for short periods 20 A
Anschluss: 4 mm safety sockets
4. Operating principle
Inside a coil the magnetic flux density B de-
pends on the number of turns n, the coil length L
and the coil current I. For an air-core coil it is
given by the equation:
L
n
I
L
I n B
⋅ ⋅ μ = ⋅ ⋅ ⋅ μ =
0 0
1
(1)
The magnetic field constant is
6
0
10 256637 , 1 ⋅ = μ Vs/Am.