What is pole strength of a bar magnet ? Show the magnetic dipole moment in terms of pole strength.
What is pole strength of a bar magnet ? Show the magnetic dipole moment in terms of pole strength.
The strength of magnetic pole is called pole strength.
Magnetic dipole moment per unit length of magnet is called pole strength of magnet.
Charge $q$ is like that in equations of static electricity, likewise pole strength is in magnetism.
Pole strength is denoted by $q_{m}$ or $P$.
Pole strength depend on the type of material of magnet, its magnetization position and area of cross section $(A)$ of magnet.
It is a scalar quantity.
The unit of pole strength is ampere meter $(Am)$.
If the length of bar magnet is $(2l)$ and pole strength $q_{m}$ then magnetic dipole moment, $\vec{m}=q_{m}(\overrightarrow{2 l})$
The direction of $\vec{m}$ is from $\mathrm{S}$ to $\mathrm{N}$.
From this equation unit of $m$ is $\mathrm{Am}^{2}$.
$\therefore q_{m}=\frac{\overrightarrow{\mathrm{F}_{m}}}{\overrightarrow{\mathrm{B}}} \quad \therefore q_{m}=\mathrm{F}_{m}[\because \mathrm{B}=1 \mathrm{~T}]$
and $\overrightarrow{\mathrm{F}_{m}}=\left(q_{m}\right)(\overrightarrow{\mathrm{B}})$
(This equation is similar to static electricity as per $\vec{F}=q(\vec{E})$ ).
Similar Questions
Two identical bar magnets are fixed with their centres at a distance $d$ apart. A stationary charge $Q$ is placed at $P$ in between the gap of the two magnets at a distance $D$ from the center $O$ as shown in the figure. The force on the charge $Q$ is
Two identical bar magnets are fixed with their centres at a distance $d$ apart. A stationary charge $Q$ is placed at $P$ in between the gap of the two magnets at a distance $D$ from the center $O$ as shown in the figure. The force on the charge $Q$ is
- [AIPMT 2010]
Assume the dipole model for earth’s magnetic field $\mathrm{B}$ which is given by
${{\rm{B}}_{\rm{v}}} = $ vertical component of magnetic field
$ = \frac{{{\mu _0}}}{{4\pi }}\frac{{2m\,\cos \theta }}{{{r^3}}}$
${{\rm{B}}_H} = $ Horizontal component of magnetic field
${{\rm{B}}_H} = \frac{{{\mu _0}}}{{4\pi }}\frac{{m\,\sin \theta }}{{{r^3}}}$
$\theta $ $= 90^{°}$ -latitude as measured from magnetic equator.
$(a)$ Find loci of points for which : $\left| {{\rm{\vec B}}} \right|$ is minimum;
Assume the dipole model for earth’s magnetic field $\mathrm{B}$ which is given by
${{\rm{B}}_{\rm{v}}} = $ vertical component of magnetic field
$ = \frac{{{\mu _0}}}{{4\pi }}\frac{{2m\,\cos \theta }}{{{r^3}}}$
${{\rm{B}}_H} = $ Horizontal component of magnetic field
${{\rm{B}}_H} = \frac{{{\mu _0}}}{{4\pi }}\frac{{m\,\sin \theta }}{{{r^3}}}$
$\theta $ $= 90^{°}$ -latitude as measured from magnetic equator.
$(a)$ Find loci of points for which : $\left| {{\rm{\vec B}}} \right|$ is minimum;
Write the equation of magnetic field on the axis of current carrying finite solenoid.
Write the equation of magnetic field on the axis of current carrying finite solenoid.
Magnetic lines of force due to a bar magnet do not intersect because
Magnetic lines of force due to a bar magnet do not intersect because
The diagram shows magnetic field lines. We move from above to below and back.Below shows the graph of variaton of magnetic flux with time. We will measure the flux of
The diagram shows magnetic field lines. We move from above to below and back.Below shows the graph of variaton of magnetic flux with time. We will measure the flux of