Question

Why are overhead cables not insulated?

• A. Because air is a bad conductor of electricity.
• B. Because air is a good conductor of electricity.
• C. Bare wires conduct electricity better.
• D. Both (B) and (C).

Answer 1

The correct option is A Because air is a bad conductor of electricity.

As air is a bad conductor of electricity, it naturally insulates the transmission lines and hence insulation is not required for overhead cables.
Also, overhead transmission lines have extremely high voltage and it would require a very thick insulation to absorb the heat produced by such high voltage.