NEET-XII-Physics

37: Magnetic Properties of Matter

with Solutions - page 2
Qstn# iii-4 Prvs-QstnNext-Qstn
  • #4
    Which of the following pairs has quantities of the same dimensions?
    (a) Magnetic field B and magnetising field intensity H
    (b) Magnetic field B and intensity of magnetisation I
    (c) Magnetising field intensity H and intensity of magnetisation I
    (d) Longitudinal strain and magnetic susceptibility
    digAnsr:   c,d,a,b
    Ans : (c) Magnetising field intensity H and intensity of magnetisation I
    (d) Longitudinal strain and magnetic susceptibility
    Dimension of Magnetic field B is given by,
    F=Bqv
    `` \Rightarrow ```` B=\frac{F}{qv}``
    `` \Rightarrow ```` \frac{\left[{\,\mathrm{\,MLT\,}}^{-2}\right]}{\left[\,\mathrm{\,AT\,}\right]\left[{\,\mathrm{\,LT\,}}^{-1}\right]}=\left[{\,\mathrm{\,MT\,}}^{-2}{\,\mathrm{\,A\,}}^{-1}\right]``
    Dimension of magnetising field intensity H is given by,
    H=`` \left[\frac{Idl}{{r}^{2}}\right]``
    `` \Rightarrow ```` \frac{\left[\,\mathrm{\,AL\,}\right]}{\left[{\,\mathrm{\,L\,}}^{2}\right]}=\left[{\,\mathrm{\,AL\,}}^{-1}\right]``
    Dimension of intensity of magnetisation I is also `` \left[{\,\mathrm{\,AL\,}}^{-1}\right]`` as both Magnetising field intensity H and intensity of magnetisation I are measured in Am`` -1``.
    Hence, option
    (a) and option
    (b) is incorrect. Option
    (c) is correct.
    As Longitudinal strain and magnetic susceptibility both are dimensionless quantity. Hence, option
    (d) is correct.
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