Tag: classification of magnetic material

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Questions Related to classification of magnetic material

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

Magnetic permeability of paramagnetic substances is?

  1. $0$

  2. $> 1$

  3. $< 1$

  4. $1$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Paramagnetic substances are substances which are weakly attracted by the magnetic field when they are placed in an external magnetic field. Magnetic permeability of paramagnetic substances is slightly greater than one whereas that of diamagnetic materials is slightly less than one.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

How will you quantize the relative permeability of a paramagnetic substance ?

  1. Much more than one

  2. Slightly more than one

  3. Less than one but greater than zero

  4. Zero
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Paramagnetic substances are those which are attracted slightly in the direction of the magnetic field. As such, the magnetic permeability of these materials is slightly greater than $1$. 
Similarly, diamagnetic materials are those which are repelled slightly away from the direction of magnetic field. These materials have their permeability slightly less than $1$.
And ferromagnetic materials are those which are attracted very strongly and their permeabilities are much higher than $1$.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

The relative permeability is represented by $\mu _r$ and the susceptibility by $\chi$ for a magnetic substance. Then, for a paramagnetic substance. Then, for a paramagnetic substance 

  1. $\mu _r> 1, \chi >0$

  2. $\mu _r> 1, \chi < 0$

  3. $\mu _r > 1, \chi >0$

  4. $\mu _r < 1, \chi < 0$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Susceptence $(\chi) = \dfrac{B-B _0}{B _0}$


Where $B _0$ is external applied magnetic field and $B$ is magnetic field in presence of paramagnetic substance.
Since dipoles in paramagnetic substance align in direction of applied magnetic filed, therefore $B > B _0$

And $B$ is bit more than $B _0$
$\Rightarrow \chi > 0$

And also $\mu _r = \chi + 1$
$\Rightarrow \mu _r  > 0 + 1$
$ \Rightarrow \mu _r > 1$
Therefore option A is correct.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

According to  molecular orbital theory, the paramagnetism of $O _{2}$  molecule is due to presence of 

  1. Unpaired electrons in the bonding $\sigma $ molecular orbital

  2. Unpaired electrons in the anti- bonding $\sigma $ molecular orbital

  3. Unpaired electron in the bonding $\pi $ molecular orbital

  4. Unpaired electrons in the anti - bonding $\pi $ molecular obrital
Reveal answer Fill a bubble to check yourself
A Correct answer