InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following is the correct expression for Curie’s law?(a) χ = Cμ0T(b) χ = Cμ0/T(c) μ0 = C χ T(d) μ0 = C χ /T |
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Answer» Right choice is (b) χ = Cμ0/T To explain: The expression, χ = Cμ0/T, is the correct expression for the Curie’s law. It shows that, for a paramagnetic material, both χ and μ depend not only on the material, but also on the sample temperature. |
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| 2. |
Curie’s law is applicable at every point on a Paramagnetic Material.(a) True(b) FalseThis question was posed to me in final exam.This intriguing question comes from Classification of Magnetic Materials in division Magnetic Properties of Materials of Engineering Physics II |
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Answer» Right option is (b) False The explanation: As the field is increased or the temperature is lowered, the magnetization increases until it reaches the saturation value, at which point all the dipoles are perfectly aligned with the field. Beyond this, Curie’s law is no longer valid. |
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| 3. |
Materials in which magnetization persists even after the field has been removed are called ___________(a) Diamagnetic(b) Paramagnetic(c) Soft Ferro magnets(d) Hard Ferro magnets |
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Answer» Right answer is (d) Hard Ferro magnets Explanation: In Hard Ferro magnets, even after the magnetic field has been removed, the magnetization persists. Alnico is one such material. |
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| 4. |
If the number of atoms in the domain in ferromagnetic iron, in the form of a cube of side length 1μm, is 8.65 X 10^10 atoms and dipole moment of each iron atom is 9.27 X 10^-24 Am^2, what is the maximum Magnetization of the domain?(a) 6 X 10^5 A/m(b) 7 X 10^5 A/m(c) 8 X 10^5 A/m(d) 9 X 10^5 A/m |
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Answer» The correct choice is (c) 8 X 10^5 A/m Best explanation: Now, we know the maximum dipole moment = N X m Mmax = 8.65 X 10^10 X 9.27 X 10^-24 = 8 X 10^-13 Am^2 Volume = (10^-6)^3 = 10^-18 m^3 Therefore, Magnetization = Mmax/ Volume = 8 X 10^-13 Am^2/10^-18 m^3 = 8 X 10^5 A/m. |
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| 5. |
Which of the following conditions are desired in the core of an electromagnet?(a) High permeability and High retentivity(b) Low permeability and High retentivity(c) High permeability and Low retentivity(d) Low permeability and Low retentivity |
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Answer» Right choice is (c) High permeability and Low retentivity Easy explanation: Ferromagnetic materials have high permeability and low retentivity. Due to these properties, the core of electromagnets is made up of ferromagnetic materials. |
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| 6. |
Superconductors are diamagnetic materials.(a) True(b) FalseI have been asked this question in an internship interview.Asked question is from Classification of Magnetic Materials in division Magnetic Properties of Materials of Engineering Physics II |
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Answer» Right choice is (a) True Easy explanation: Diamagnetic materials cooled to very low temperatures exhibits both perfect conductivity and perfect diamagnetism. Here the field lines are completely expelled. They are called superconductors. |
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| 7. |
What does the following curve show?(a) Magnetization curve(b) Hysteresis curve(c) Polarizing curve(d) Coercive Curve |
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Answer» The correct choice is (b) Hysteresis curve For explanation: The given figure is the diagram of a hysteresis curve. It shows that for a given value of H, B is not unique but depends on the previous history of the sample. This phenomenon is called hysteresis. |
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| 8. |
What will happen with magnetic materials is kept in an external magnetic field?(a) They will move(b) They will develop magnetic lines of force(c) They will create a permanent magnetic moment(d) They will be unaffected |
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Answer» Correct answer is (c) They will create a permanent magnetic moment Easy explanation: Magnetic materials are the materials which can behave like magnets. When these materials are kept in an external magnetic field, they will create a permanent magnetic moment in it. |
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