Physics - Magnetic and Superconducting Materials - Important Solved Problems(Sum): Magnetic and Superconducting Materials
SOLVED PROBLEMS
A paramagnetic material has a magnetic field
intensity of 10^{4} Am^{–1}. If the susceptibility of the
material at room temperature is 3.7 × 10^{–5}. Calculate the
magnetization and flux density in the material.
A
magnetic material has a magnetization of 2300 A m^{–1} and produces a
flux density of 0.00314 Wb m^{–2}. Calculate the magnetizing force and
the relative permeability of the material.
Solution :
Given
data:
Magnetization M = 2300 A m^{–1}
Flux
density B = 0.00314 Web m^{–2}.
A paramagnetic material has FCC structure with a
cubic edge of 2.5 A°. If the saturation value of magnetization is 1.8 × 10^{6}
A m^{–1}, Calculate the magnetization contributed per atom in Bohr
magnetrons.
The saturation magnetic induction of Nickel is 0.65
Wb m^{–2}. If the density of Nickel is 8906 kg m^{–3} and its
atomic weight is 58.7, calculate the magnetic moment of the Nickel atom in Bohr
magnetron.
Solution:
Given
data:
Saturation
magnetic induction of Nickel
In a magnetic material the field strength is found
to be 10^{6} A m^{–1}. If the magnetic susceptibility of the
material is 0.5 × 10^{–5}, calculate the intensity of magnetization and
flux density in the material.
A superconducting tin has a critical temperature of
3.7 K at zero magnetic field and a critical field of 0.0306 Tesla at 0 K. Find
the critical field at 2 K.
7. Calculate the critical current and current
density for a wire of a lead having a diameter of 1 mm at 4.2 K. The critical
temperature for lead is 7.18 K and H = 6.5 × 10^{4 }A m^{–1}.
Prove
that susceptibility of superconductor is -1 and relative permeability is zero.
Find the
critical current which can pass through a long thin superconducting wire of
aluminum of diameter 2 mm, the critical magnetic field for aluminum is 7.9 × 10^{3}
A m^{–1}.
The superconducting transistion temperature of Lead
is 7.26 K. The initial field at 0 K is 64 × 10^{3} Amp m^{–1}.
Calculate the critical field at 5 K.
A magnetic field of 2000 Amp m^{–1} is
applied to a material which has a susceptibility of 1000. Calculate the (i)
Intensity and (ii) Flux density.
The superconducting transition temperature of lead
of 7.26 K. The initial field at 0 K is 64 × 10^{3} Amp m^{–1}.
Calculate the critical field at 5 K.
The magnetic field strength of Silicon is 1500 Amp
m^{–1}. If the magnetic susceptibility is (–0.3 × 10^{–5}),
calculate the magnetization and flux density in Silicon.
14. Calculate the critical current which can flow
through a long thin super conducting wire of diameter 1 mm. The critical
magnetic field is 7.9 × 10^{3} Amp m^{–1}.
ASSIGNMENT
PROBLEMS
1.The
saturation value of magnetization of iron is 1.76 × 10^{6} A m^{–1}.
Iron had body centered cubic structure with an elementary edge of 2.86
Å.Calculate the average number of Bohr magnetrons contributed to the
magnetization per atom.
(Ans: 2.2 Bohr magnetron per
atom)
2.The
magnetic field intensity of a ferric oxide piece is 10^{6} A m^{–1}.
If the susceptibility of the material at room temperature is 10.5 × 10^{–3},
calculate the flux density and magnetization of the material.
(Ans: B = 1.259 T and M = 1500 A
m^{–1} )
3. A magnetic material has a magnetization of 3000 A m^{–1}
and flux density of 0.044 Wb m^{–2}. Calculate the magnetic force and
the relative permeability of the
material. (Ans: M = 203 and _{r }= 17.26)
Calculate the magnetic filed in the lead at 5 K, if
it’s critical magnetic field at 0 K H0 = 8 × 10^{5} A m^{–1},
and transition temperature T_{C} = 7.26 K
(Ans: 4.2 × 10^{5} A m^{–1})
The critical temperature T_{C} for mercury
with isotopic mass 199.5 is 4.185 K. Calculate its critical Temperature, when
it’s isotopic masses changes to 203.4.
(Ans: 4.139 K)
Calculate
the critical current which can flow though a long thin superconducting wire of
aluminum of diameter 1 mm. The critical magnetic field for aluminum is 7.9 × 10^{3}
A m^{–1}.