Curie's law can be written as

The materials suitable for making electromagnets should have

Needles $N_1, N_2$ and $N_3$ are made of a ferromagnetic,a paramagnetic and a diamagnetic substance respectively. $A$ magnet when brought close to them will

$A$ ferromagnetic material is heated above its $Curie$ temperature. The correct statement from the following is that

Which of the following statements are correct?
$(A)$ Electric monopoles do not exist whereas magnetic monopoles exist.
$(B)$ Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined.
$(C)$ Magnetic field lines are completely confined within a toroid.
$(D)$ Magnetic field lines inside a bar magnet are not parallel.
$(E)$ $\chi = -1$ is the condition for a perfect diamagnetic material,where $\chi$ is its magnetic susceptibility.
Choose the correct answer from the options given below:

Materials suitable for permanent magnets should have