Concept:Soft iron is chosen for an electric bell armature because it can be easily magnetised and quickly demagnetised.
Explanation:When current flows, the electromagnet attracts the soft iron armature, causing the hammer to strike the bell.
When the circuit breaks, the armature must return to its original position immediately.
Soft iron has low retentivity, so it does not retain magnetism after the current stops.
Because it loses its magnetism readily, the armature is released at once and the bell can ring repeatedly.
If the armature retained magnetism, it would stick and the bell would stop ringing.
Answer:B. It loses its magnetism readily