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A small resistor R (say, a lamp) is usua...

A small resistor R (say, a lamp) is usually put in parallel with the current carrying coil of an electromagnet, fig. What prupose does it serve ?

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When current in the coil of a large electromagnet is switched off, magnetic flux changes at a very high rate. Therefore, induced e.m.f. is very high and may cause sparking which would damage the insulation. The small resistor R placed in parallel provides a conducting path to the e.m.f. induced. In this way, risks of hight voltages and sparking ete. are reduced.
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