A small permanent magnet is always liable to become demagnetized, or have its polarity reversed by the action of lightning. [Please select]
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The moment the current is cut off, the bar is demagnetized. [Please select]
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But when the armature moves over to the magnet, the connection is broken between the screw (I) and armature (D), so that the cores of the magnets are demagnetized and lose their pull, and the spring (E) succeeds in drawing back the armature. [Please select]
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