Relative permittivity and permeability of a material are \varepsilon _{r}\; and \; \mu _{r} ,  respectively. Which of the following values of these quantities are allowed for a diamagnetic mateiral?

  • Option 1)

    \varepsilon _{r}=1.5,\; \mu _{r}=1.5

  • Option 2)

    \varepsilon _{r}=0.5,\; \mu _{r}=1.5

  • Option 3)

    \varepsilon _{r}=1.5,\; \mu _{r}=0.5

  • Option 4)

    \varepsilon _{r}=0.5,\; \mu _{r}=0.5

 

Answers (1)
P Prateek Shrivastava

As we learnt in

Relative Permeability -

\mu _{r}=\frac{\mu }{\mu _{0}}

- wherein

\mu - relative permeability of any medium

\mu_0 - relative permeability of air or vaccum

 

 

Magnetic Permeability -

\mu =\mu _{o}\mu _{r}

- wherein

\mu _{0} - absolute permeability of air 

\mu _r - relative permeability

\mu _{0}=4\pi \times 10^{-7} tesla m/amp

Magnetic Permeability

 

 

The values of relative permeability of diamagnetic materials are slightly less than 1 and \varepsilon _{r} is quite high. According to the table given,

one takes  \varepsilon _{r}=1.5\: and\; \mu _{r}=0.5.Then \; the\; choice (c) \; is \; correct.


Option 1)

\varepsilon _{r}=1.5,\; \mu _{r}=1.5

Incorrect

Option 2)

\varepsilon _{r}=0.5,\; \mu _{r}=1.5

Incorrect

Option 3)

\varepsilon _{r}=1.5,\; \mu _{r}=0.5

Correct

Option 4)

\varepsilon _{r}=0.5,\; \mu _{r}=0.5

Incorrect

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