Concept:In the double-stroke method, a moving south pole leaves a north polarity at the end of the steel bar where the stroke finishes.
Explanation:The two south poles stroke the steel bar symmetrically from the middle towards the ends
X and
Y.
As each south pole moves across the steel, it aligns the magnetic domains by inducing a north pole in the part of the bar nearest to it.
Since both ends are stroked by south poles in the same way, each end receives the same final polarity.
Therefore, the polarity at
X is north, and the polarity at
Y is also north.
Answer:X = north,
Y = north (Option C).
