Tag: magnetism and matter

Questions Related to magnetism and matter

Relative permittivity and permeability of a material are $\varepsilon _{r}$ and $\mu _{r}$ respectively. The values of these quantities allowed for a diamagnetic material are

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. $\varepsilon _{r}=0.5,\mu _{r}=1.5$

  2. $\varepsilon _{r}=1.5,\mu _{r}=0.5$

  3. $\varepsilon _{r}=0.5,\mu _{r}=0.5$

  4. $\varepsilon _{r}=1.5,\mu _{r}=1.5$

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Correct Option: B
Explanation:

For diamagnetic material
$0\leq \mu _{r}< 1$
And for any material, $ \varepsilon _{r}> 1$

So, option B.

Magnetism is a property present in ___________.

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. Only a few materials

  2. Only ferromagnetic material

  3. Only paramagnetic material

  4. All materials

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Correct Option: D
Explanation:

Magnetization is present in all materials. It is a class of physical phenomenon that is mediated by Magnetic fields.

The magnetic state of different materials depends on temperature and other variables such as pressure and applied magnetic field.

 

Relative permittivity and permeability of a material are $\epsilon _{\mathrm{r}}$ and $\mu _{\mathrm{r}}$, respectively. Which of the following values of these quantifies are allowed for a diamagnetic material? 

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. $\epsilon _{\mathrm{r}}=0.5,\ \mu _{\mathrm{r}}=0.5$

  2. $\epsilon _{\mathrm{r}}=1.5,\ \mu _{\mathrm{r}}=1.5$

  3. $\epsilon _{\mathrm{r}}=0.5,\ \mu _{\mathrm{r}}=1.5$

  4. $\epsilon _{\mathrm{r}}=1.5,\ \mu _{\mathrm{r}}=0.5$

Show answer
Correct Option: D
Explanation:

For a diamagnetic material, $\mu _r$ and $\epsilon _r$ should have following bounds $0<\mu _r <1$ and for any material $\epsilon _r >1$

Needles $N _{1}, N _{2}$ and $N _{3}$ are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. A magnet when brought close to them will 

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. attract all three of them.

  2. attract $\mathrm{N} _{1}$ and $\mathrm{N} _{2}$ strongly but repel $\mathrm{N} _{3}$. 

  3. attract $\mathrm{N} _{1}$ strongly, $\mathrm{N} _{2}$ weakly and repel $\mathrm{N} _{3}$ weakly.

  4. attract $\mathrm{N} _{1}$ strongly, but repel $\mathrm{N} _{2}$ and $\mathrm{N} _{3}$ weakly.

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Correct Option: C
Explanation:

Ferromagnetic substances are strongly attracted by a magnet while, paramagnetic and diamaganetic substances are weakly attracted and repelled respectively.

Curie temperature is the temperature above which 

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. a ferromagnetic material becomes paramagnetic

  2. a paramagnetic material becomes diamagnetic

  3. a ferromagnetic material becomes diamagnetic

  4. a paramagnetic material becomes ferromagnetic.

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Correct Option: A
Explanation:

The Curie temperature is the temperature above which ferromagnetic materials lose their permanent magnetic field, the magnetism completely disappears. Above Curie temperature, the material behaves para-magnetically.

A ferromagnetic material is placed in an external magnetic field. The magnetic domains 

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. Increase in size

  2. Decrease in size

  3. May increase or decrease is size

  4. Have no relation with the field

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Correct Option: A

The magnetic susceptibility is negative for

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. Paramagnetic materials only

  2. Diamagnetic material only

  3. Ferromagnetic materials only

  4. paramagnetic and ferromagnetic materials

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Correct Option: B

Which of the following species is para-magnetic

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. A carbonium ion

  2. A free radical

  3. A carbonium

  4. All of these

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Correct Option: A

The relative permeability of silicon is $0.99837$ and that of palladium is $1.00692$, choose the correct option from the following :

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. silicon is paramagnetic and palladium is ferromagnetic

  2. silicon is ferromagnetic and palladium is paramagnetic

  3. silicon is diamagnetic and palladium is paramagnetic

  4. Both are paramagnetic

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Correct Option: C
Explanation:

Diamagnetic           Paramagnetic             Ferromagnetic
-1 $\leq$ $\chi$ < 0                  0 < $\chi$ < $\varepsilon$                  $\chi$ >> 1
0 $\leq$ $\mu _{r}$ < 1                1 < $\mu _{r}$ < 1+ $\varepsilon$               $\mu _{r}$ >> 1
$\chi$ $=$ magnetic susceptibility
$\mu _{r}$ $=$ relative permeability.
$\varepsilon$ < 1 and small.

The relative permeability of a material is $0.9$. The material is

physics magnetism and matter magnetic materials behaviour of substances in magnetic field classification of magnetic materials

  1. diamagnetic

  2. para magnetic

  3. ferro magnetic

  4. non-magnetic

Show answer
Correct Option: A
Explanation:

diamagnetic material
$-1\leq \chi < 0$
0 $\leq$ $\mu$ < 1
$\chi$ $=$ Magnetic susceptibility
$\mu$ $=$ permeability