Two identical bar magnets with a length of 10 | vedclass

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(A) The weight of the upper magnet is balanced by the magnetic repulsive force between the two magnets.Let $m$ be the pole strength and $r$ be the dis

Vedclass · Accepted Answer

$6.64$

Vedclass · Answer

(A) The weight of the upper magnet is balanced by the magnetic repulsive force between the two magnets.Let $m$ be the pole strength and $r$ be the distance between the nearest poles.The repulsive force $F = \frac{\mu_0}{4\pi} \cdot \frac{m^2}{r^2}$.Given: $m_{mass} = 50 \, g = 0.05 \, kg$,$r = 3 \, mm = 3 	imes 10^{-3} \, m$,$g = 9.8 \, m/s^2$.Equating force to weight: $\frac{\mu_0}{4\pi} \cdot \frac{m^2}{r^2} = m_{mass} \cdot g$.$10^{-7} \cdot \frac{m^2}{(3 	imes 10^{-3})^2} = 0.05 	imes 9.8$.$10^{-7} \cdot \frac{m^2}{9 	imes 10^{-6}} = 0.49$.$m^2 = \frac{0.49 	imes 9 	imes 10^{-6}}{10^{-7}} = 0.49 	imes 9 	imes 10 = 44.1$.$m = \sqrt{44.1} \approx 6.64 \, A \cdot m$.

List-$I$	List-$II$
$(A)$ Magnetic field intensity	$(i)$ $Wb$
$(B)$ Magnetic flux	(ii) $Wb \cdot m^{-2}$
$(C)$ Magnetic pole strength	(iii) $A \cdot m$
$(D)$ Magnetic induction	(iv) $A \cdot m^{-1}$

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