JEE Main 2025 (Online) 7th April Morning Shift | Magnetic Properties of Matter Question 2 | Physics

The percentage increase in magnetic field (B) when space within a current carrying solenoid is filled with magnesium (magnetic susceptibility $\chi_{\mathrm{Mg}}=1.2 \times 10^{-5}$ ) is :

$\frac{5}{3} \times 10^{-5} \%$

$\frac{5}{6} \times 10^{-4} \%$

$\frac{5}{6} \times 10^{-5} \%$

$\frac{6}{5} \times 10^{-3} \%$

JEE Main 2025 (Online) 3rd April Evening Shift

MCQ (Single Correct Answer)

-1

A magnetic dipole experiences a torque of $80 \sqrt{3} \mathrm{~N} \mathrm{~m}$ when placed in uniform magnetic field in such a way that dipole moment makes angle of $60^{\circ}$ with magnetic field. The potential energy of the dipole is :

$$ \text { }-40 \sqrt{3} \mathrm{~J} $$

-80 J

80 J

-60 J

JEE Main 2025 (Online) 2nd April Morning Shift

MCQ (Single Correct Answer)

-1

The relationship between the magnetic susceptibility $(x)$ and the magnetic permeability $(\mu)$ is given by :

( $\mu_0$ is the permeability of free space and $\mu_T$ is relative permeability)

$X=\frac{\mu}{\mu_0}-1$

$X=\frac{\mu_{\mathrm{r}}}{\mu_0}+1$

$\chi=\mu_r+1$