A method of demagnetization is
A
placing the magnetic bar in a solenoid
B
double-stroking the magnet with soft in n-s direction
C
heating a magnetic bar red hot and allowed to cool e-w direction
D
hammering the magnetic bar repeatedly in n-s direction
Verified Correct Answer: C.
Physical Principles & Numerical Solution
This process disrupts the alignment of magnetic domains, effectively demagnetizing the bar.
Source: Official Exam / Past Question Archive