Mini stereo speaker cables are made of copper wire surrounded by robert electricity travel down the copper portion of the cable while the rubber protects you from being zapped by the electricity which physical property explains the difference in ability of copper and rubber to transmit electricity

Here current is flowing through the copper wire so this shows that copper is good conductor of electricity.

It is having less resistance as it conducts the current easily

Now a rubber coating on it will protect us from electric shock

So this property shows that rubber is a bad conductor of electricity

It is having large electrical resistance due to which it will conduct no current

Rubber : - No transmittance of electricity

copper :- good transmittance of electricity