Answers

2015-10-29T17:45:43+05:30
We remove the plastic coating of connecting wires before making circuits because the plastic coating acts as an insulator. As insulators does not conduct electricity, we remove them. The copper wires, which conducts electricity makes joints to create a circuits. 
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2015-10-29T18:59:20+05:30
We remove plastic coating of connecting wires before making circuit because it is an insulator and we know that insulators doesn't allow electricity to pass through them. so plastic does't allow electricity to pass through it which leads to the break down of circuit.
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