How it works
An electrical cable is one or more conductors, each in its own insulation, inside a protective jacket. This drawing names four parts of a three-conductor power cable, then four more inside a coaxial cable.
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A power cable, then a coaxial cable
A power cable has three main parts: conductors, insulation and a jacket. Filler strands may be packed into the gaps to keep it round. A coaxial cable, the kind that carries television signals, has one center conductor. Round it come the dielectric, a shield, often a thin foil covered by a braid, and the jacket. The dielectric keeps the spacing between the center conductor and the shield.
- Insulation or jacket? Insulation covers one wire; the jacket covers them all.
- Insulation and dielectric are both insulators; dielectric is the name used inside a coaxial cable.
Questions and answers
What are the parts of a cable called?
A cable has three main parts: the conductors, which carry the current, the insulation round each conductor, and a protective jacket, or sheath, over them all. Some cables add fillers and a metal shield.
What are the layers of a coaxial cable?
From the middle out: the center conductor, the dielectric, the shield and the jacket. The shield is often a thin foil covered by a braid of fine wires.
What is the outer covering of a cable called?
The jacket, also called the sheath. It protects what is inside, and its material is chosen for the conditions the cable will meet, such as water, sunlight or knocks.
What is the dielectric in a coaxial cable?
The insulating layer between the center conductor and the shield. It keeps the spacing between the two the same along the cable.
Why is a cable conductor made of strands?
Small wires twisted together make a conductor that bends more easily than one solid wire of the same size.