The correct answer is: D. All of the above
Dielectric losses in cable insulation are caused by the movement of electrons through the insulation material. This movement creates heat, which can cause the insulation to degrade over time.
Losses in the conductor are caused by the resistance of the conductor material. This resistance causes heat to be generated, which can also cause the conductor to degrade over time.
Losses in the metallic sheathings and armourings are caused by the resistance of these materials. This resistance causes heat to be generated, which can also cause the sheathings and armourings to degrade over time.
All of these sources of heat generation can contribute to the overall heat load on a cable. This heat load can cause the cable to overheat, which can lead to a number of problems, including:
- Degradation of the insulation material
- Degradation of the conductor material
- Deformation of the cable
- Fire
To prevent these problems, it is important to select cables that are designed for the specific application. The cable should have an insulation material that is suitable for the operating temperature and voltage. The conductor material should also be suitable for the operating temperature and voltage. The cable should also be properly installed and maintained.