JAMB - Physics (2025 - No. 100)
A method of demagnetization is
placing the magnetic bar in a solenoid
double-stroking the magnet with soft in n-s direction
heating a magnetic bar red hot and allowed to cool e-w direction
hammering the magnetic bar repeatedly in n-s direction
Giải thích
This process disrupts the alignment of magnetic domains, effectively demagnetizing the bar.