greatfull for you, this material basephysics 2. materi tentang medan magnet pada arus listrik. versi english.

1. Based physics II Lecturer Mr.syuhendri, M.Pd.
MAGNETIC FIELD BY THE FLOW LISTRIK
Nine Group
Intan Megawati
Putri Marisa
Dian Irawan
@copyright by nine group basic physic II

2. DIAGRAM MATERIAL
II. BY FIELD
I. Biot Savart Law
magnetic dipole
IV.FORCE BETWEEN TWO
STRAIGHT WIRE-flowing
III. AMPERE’S LAW
parallel

3. 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:
I
dl Ѳ P
µ0 = permeability of vacuum
r
= 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.

4. Biot Savart formulation with vector notation is :
I
p
Ѳ
dl r
d Bp
r2
r1
p1 I P2

5. =i
Magnetic field formed by a loop current. Magnetic field by a circular loop on the axis of
Here we will see an equal influence the circle, in the image above is to point P1:
magnetic dipole (on the magnetic field)
with electric dipole effect (on the
electric field).
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:
,m  iA

6. are:
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 p  qd
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 m
are:

7. So, is defined magnetic dipole associated with the current in a closed loop,
namely:
m
Magnetic dipole m  iA
magnitude A is the loop cross-sectional area, A is the appropriate
direction of screw rotation direction of flow.

8. 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:
B
I
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
dl
I

9. 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
From the results , It appears that
B is inversely proportional to r and
the results are in accordance with
the Law of Biot Savart.
So, B

10. There are two wires have current, respectively bring currents I 'and I in the
same direction.
I I
x x
x x
x x by wire (1)
B
x x
(1) (2)
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: