Insulated electrical wires often have a maximum voltage rating,i.e.,the insulation on the wire is safe up to the rated voltage.The reason why the insulator is not safe at higher voltage is because
A)there is a possibility of electric breakdown,which will cause electrons in the valence band of the insulator to be promoted to the conduction band making the insulator a conductor.
B)the wire will then carry more current,making the wire unsafe.
C)most households only have 240 V maximum so there is no point having a higher voltage rating.
D)it is the manufacturer's way of preventing users from transmitting higher voltage.
E)None of these is correct.

Question

Quizplus · Accepted Answer

Insulation on an electrical wire is designed to prevent current from escaping the wire and coming into contact with other conductive materials. However, if the voltage exceeds the maximum voltage rating of the insulation, the electric field becomes too strong and can cause electric breakdown, which allows electrons in the valence band of the insulator to be promoted to the conduction band, making the insulator a conductor. This can create a dangerous situation, which is why insulation is rated for a maximum voltage.

Insulated Electrical Wires Often Have a Maximum Voltage Rating,i