29.11: Questions

Last updated
Save as PDF

Page ID: 32856

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

Quick questions

You should be able to answer these questions without too much difficulty after studying this TLP. If not, then you should go through it again!

Which picture best describes ferromagnetism?

Answer: B. In a ferromagnetic material below the Curie temperature all the dipole moments are aligned parallel to each other.

Which 3 elements are ferromagnetic at room temperature?

Answer: C. There are only 4 ferromagnetic elements at room temperature. Of these, iron (Fe), nickel (Ni), and cobalt (Co) are shown above. The fourth is gadolinium (Gd).

What happens to ferromagnetic materials above the Curie Temperature?

Answer: D. Above the Curie temperature there is a large enough contribution from the thermal energy to overcome the cooperative ordering of the magnetic dipole moments and so the material becomes paramagnetic.

What is the main driving force for the formation of domains?

Answer: A. While domains do form to minimize the total energy, the principal driving force is the Magnetostatic energy. The magnetocrystalline energy and magnetostrictive energy influence the shape and size of the domains.

a	Mn, Cr, Fe
b	Mg, Ti, Ni
c	Fe, Ni, Co
d	Co, Ce, Mn

a	They become diamagnetic
b	They become gases
c	They become antiferromagnetic
d	They become paramagnetic

a	Magnetostatic energy
b	Magnetocrystalline energy
c	Magnetostrictive energy
d	All of the above