medan magnet dari aliran listrik
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greatfull for you, this material basephysics 2. materi tentang medan magnet pada arus listrik. versi english.TRANSCRIPT
MAGNETIC FIELD BY THE FLOW LISTRIK
Based physics II Lecturer Mr.syuhendri, M.Pd.
Nine Group
Intan Megawati Putri Marisa Dian Irawan
@copyright by nine group basic physic II
I. Biot Savart Law II. BY FIELD
magnetic dipole
III. AMPERE’S LAW
IV.FORCE BETWEEN TWO STRAIGHT WIRE-flowing
parallel
DIAGRAM MATERIAL
I. Biot Savart Law Hans Christian Oersted in 1819 has been observed that a compass needle would deviate him if placed near an electrical current. This shows that the electric currents affect the direction maget field, so the electric current causes a magnetic field. From the Biot and Savart experiment in 1820 found that the magnetic fields around electric current can be formulated as follows:
µ0 = permeability of vacuum = 4π x 10-7 Wb A-1 m-1 = 4π x 10-7 Tm A-1
The direction of dB is perpendicular both to the dl, or against the r.
I
dl r
P Ѳ
Biot Savart formulation with vector notation is :
I
dl Ѳ
pBd
p
r
r2 r1
I p1 P2
Magnetic field formed by a loop current. Here we will see an equal influence magnetic dipole (on the magnetic field) with electric dipole effect (on the electric field).
Magnetic field by a circular loop on the axis of the circle, in the image above is to point P1: Directions Bp1 is unidirectional A. For a very distant point P, x > P, then R2 + x2 = x2 so that the magnetic field in P1 expression can be written as follows:
= i
Aim ,
The results we get above a lot like the electric field generated by an electric dipole: The electric field at P by the electric dipole The electric field at P by the electric dipole By analogy to the dipole magnetic and electric fields that result, we consider an arbitrary point, for example P2. The magnetic field in P2 by a magnetic dipole are:
dqp
are:
are:
m
Aim
So, is defined magnetic dipole associated with the current in a closed loop,
namely:
Magnetic dipole
magnitude A is the loop cross-sectional area, A is the appropriate
direction of screw rotation direction of flow.
m
However, Ampere's law can only be used at currents that generate the magnetic
field with a certain symmetry. For example on a very fast-flowing straight wire
length:
We know that the magnetic field surrounding a long straight wire-flowing is
trending in the direction of rotation as the screws (see picture) and the
same amount at every point, a distance equal to the wire. Because it is so
that, to choose a closed path sectional area of a circle that is
perpendicular to the wire circle and centered on the wire.
B
I
ld
B
I
We apply the Law of amperes as follows:
·
¤ dl is an element in the circular trajectory, the direction of dl is selected equal to B so that B.dl = Bd ¤ Iin is the current which is surrounded by a closed path that we choose. thus
, because B is constan
So, B
From the results , It appears that B is inversely proportional to r and the results are in accordance with the Law of Biot Savart.
There are two wires have current, respectively bring currents I 'and I in the same direction. by wire (1) Wire (1) will cause B field around it. On the wire (2), there are positive charges flow in the direction of the current direction I, or the flow of negative charge in the opposite direction I. wire (2) will get a magnetic force towards the wire (1), a big force of unity length:
xxx
xxxxx
I I
)1( )2(
B