Question
What type of substances would make better permanent magnets, ferromagnetic or ferrimagnetic. Justify your answer.
✓
Answer
Ferromagnetic substances would make better permanent magnets. In solid state, the metal ions of ferromagnetic substances are grouped together into small regions called domains. Thus, each domain acts as a tiny magnet. In an unmagnetised piece of a ferromagnetic substance the domains are randomly oriented and their magnetic moments get cancelled. When the substance is placed in a magnetic field all the domains get oriented in the direction of the magnetic field and a strong magnetic effect is produced. This ordering of domains persists even when the magnetic field is removed and the ferromagnetic substance becomes a permanent magnet.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Give reasons for the following:
→- Ethyl iodide undergoes $S_N2$ reaction faster than ethyl bromide.
- $(\pm)$ 2-Butanol is optically inactive.
- C-X bond length in halobenzene is smaller than C-X bond length in $CH_3-X$.
Explain why the stability of oxoacids of chlorine increases in the order given below:
$HClO < HClO_2 < HClO_3 < HClO_4$
→$HClO < HClO_2 < HClO_3 < HClO_4$
A compound $(X)$ reacts with $PCl_5$ to form compound $Y.$ Compound $Y$ reacts with ethereal solution of magnesium to form compound $(Z),$ which on treating with propanone and further hydrolysis to give $2-$Methyl propan$-2-ol. $ What are the compounds $X$ and $Y$ and also give the equations of the reactions.
→What is the difference between physisorption and chemisorption?
$i.$ Define rate constant of reaction.
$ii.$ A first order reaction takes $40$ mins for $30\%$ decomposition. Calculate $t_\frac{1}{2}.$
→$ii.$ A first order reaction takes $40$ mins for $30\%$ decomposition. Calculate $t_\frac{1}{2}.$
Account for the following:
Bleaching of flowers by chlorine is permanent while that by sulphur dioxide is temporary.
Bleaching of flowers by chlorine is permanent while that by sulphur dioxide is temporary.
Examine the given defective crystal:
Answer the following questions:
Answer the following questions:
- Is the above defect stoichiometric or non-stoichiometric?
- write the term used for the electron occupied site.
- Give an example of the compound which shows this type of defect.
Shanti, a domestic helper of Mrs. Anuradha, fainted while mopping the floor. Mrs. Anuradha immediately took her to the nearby hospital where she was diagnosed to be severely ‘anaemic’, The doctor prescribed an iron rich diet and multivitamins supplement to her. Mrs. Anuradha supported her financially to get the medicines. After a month, Shanti was diagnosed to be normal.
After reading the above passage, answer the following questions:
After reading the above passage, answer the following questions:
- What values are displayed by Mrs. Anuradha?
- Name the vitamin whose deficiency causes ‘pernicious anaemia’.
- Give an example of a water soluble vitamin.
Write the chemical reactions involved in the process of extraction of Gold. Explain the role of dilute $NaCN$ and $Zn$ in this process.
→Give the equations of reaction of phenol with the following compounds:
(i) Benzene diazonium chloride
(ii) Acetone
(iii) Phthalic anhydride.
(i) Benzene diazonium chloride
(ii) Acetone
(iii) Phthalic anhydride.