by peter hill 14 years ago
681
More like this
Current creates a force
loudspeaker
Radial Field (Push up down)
Spring
Galvanometer
Axial Field (B is not a function of angle)
Force prop Current
Spring means deflection = current
DC Motor
Through Field
Comutator to change current
External Magnet
Electromagnet
Perminant
Commutator
Coil
t = BAincos(q)
n = turns
B = Field in tesla T
A = area x m times y m
i = current A
q= angle to mag field
One wire
t = Fd
Torque has units Newton meters
Vectors do not have to known
1nm clockwise
Two wires
F Force N newtons attractive
l Length m meters length of parallel wire
k 2E-7 magnetic constant
d separation m meters
I current A amps
The force of 1 N is read off the apparatus, defining the amp and thus also the coulomb
F/l = KII/D
Parallel Pull together
Anti Parallel = anti
Single wire
F = BIlSin(q)
- Field Strength (tesla T)
- I Current (amps A)
- l Length (m)
- Sin(q) angle
in x Out .
Solenoid Loop
N -> S
Solenoid finger flow in current , thumb points north
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Finger field, thumb up current, palm push
Grip wire
