Fig. 3.77.
3.283. Fig. 3.76 illustrates a basic magnetization curve of iron
(commercial purity grade). Using this plot, draw the permeability
45 sss
mommummummummummommummmilumm...---mimummummmummuummumm=ammuummom
Emmummummommuummemalsommmmummumum
0.5
ss sss PE2s ss
ss ss WCR ss ss ss
ss s IMIOss Es ss ss
sss mass s
sss MAIsss ss
ss 2ss ss
ss Usss ss
ss nss ss ss ss
sss WBsss ss ss ss
sss Usss
ss ss
ss
ss
sss Msss
ss
mmommommimmummummummommiummumm
mmummummommumummummummummum
ss
ss Esss
ss I sss ss
ss
ss
ss
ss Hsss ss ss
ss Hs ss ss pave
of
s
magoetizatioo cam mom
ss u ss
ss i ss
ss
ss iron (commercial
MI
Minumnumwmrn
.7
mummommilimmms
• rity • rade
iii
mmimmummummummommommmmimmummmommom
ss ss s
immommumummummunummummmummm
ss
MEAMMEMEMMEMMEMOMMOMMIIMMOMMOMMOIMMEMEMMM
ss
01
0.2
a3
0.4
0.5
0.5
H, Alm
Fig. 3.76.
p. as a function of the magnetic field strength H. At what value of
H is the permeability the greatest? What is ttioaa, equal to?
3.284. A thin iron ring with mean diameter d = 50 cm supports
a winding consisting of N = 800 turns carrying current I = 3.0 A.
The ring has a cross-cut of width b = 2.0 mm. Neglecting the scattering of the magnetic flux at the gap edges, and using the plot shown
in Fig. 3.76, find the permeability of iron under these conditions.
3.285. A long thin cylindrical rod made of paramagnetic with
magnetic susceptibility x and having a cross-sectional area S is
located along the axis of a current-carrying coil.
One end of the rod is located at the coil centre where
the magnetic induction is equal to B whereas the
other end is located in the region where the magnetic field is practically absent. What is the force
that the coil exerts on the rod?
3.286. In the arrangement shown in Fig. 3.77 it
is possible to measure (by means of a balance) the
force with which a paramagnetic ball of volume
V = 41 mm3 is attrabted to a pole of the electromagnet M. The magnetic induction at the axis of the
poleshoe depends on the height x as B = B o exp (—ax2), where
Bo = 1.50 T, a = 100 m-2 . Find:
(a) at what height xn., the ball experiences the maximum attraction;
4T
146
3.283. Fig. 3.76 illustrates a basic magnetization curve of iron
(commercial purity grade). Using this plot, draw the permeability
45 sss
mommummummummummommummmilumm...---mimummummmummuummumm=ammuummom
Emmummummommuummemalsommmmummumum
0.5
ss sss PE2s ss
ss ss WCR ss ss ss
ss s IMIOss Es ss ss
sss mass s
sss MAIsss ss
ss 2ss ss
ss Usss ss
ss nss ss ss ss
sss WBsss ss ss ss
sss Usss
ss ss
ss
ss
sss Msss
ss
mmommommimmummummummommiummumm
mmummummommumummummummummum
ss
ss Esss
ss I sss ss
ss
ss
ss
ss Hsss ss ss
ss Hs ss ss pave
of
s
magoetizatioo cam mom
ss u ss
ss i ss
ss
ss iron (commercial
MI
Minumnumwmrn
.7
mummommilimmms
• rity • rade
iii
mmimmummummummommommmmimmummmommom
ss ss s
immommumummummunummummmummm
ss
MEAMMEMEMMEMMEMOMMOMMIIMMOMMOMMOIMMEMEMMM
ss
01
0.2
a3
0.4
0.5
0.5
H, Alm
Fig. 3.76.
p. as a function of the magnetic field strength H. At what value of
H is the permeability the greatest? What is ttioaa, equal to?
3.284. A thin iron ring with mean diameter d = 50 cm supports
a winding consisting of N = 800 turns carrying current I = 3.0 A.
The ring has a cross-cut of width b = 2.0 mm. Neglecting the scattering of the magnetic flux at the gap edges, and using the plot shown
in Fig. 3.76, find the permeability of iron under these conditions.
3.285. A long thin cylindrical rod made of paramagnetic with
magnetic susceptibility x and having a cross-sectional area S is
located along the axis of a current-carrying coil.
One end of the rod is located at the coil centre where
the magnetic induction is equal to B whereas the
other end is located in the region where the magnetic field is practically absent. What is the force
that the coil exerts on the rod?
3.286. In the arrangement shown in Fig. 3.77 it
is possible to measure (by means of a balance) the
force with which a paramagnetic ball of volume
V = 41 mm3 is attrabted to a pole of the electromagnet M. The magnetic induction at the axis of the
poleshoe depends on the height x as B = B o exp (—ax2), where
Bo = 1.50 T, a = 100 m-2 . Find:
(a) at what height xn., the ball experiences the maximum attraction;
4T
146