Correct AnswerA. XLPE (Cross-linked polyethylene)
Quick Explanation
XLPE is widely used as insulation in modern medium- and high-voltage power cables because cross-linking improves thermal capability, dielectric performance and mechanical stability compared with ordinary polyethylene/PVC.
Detailed Explanation
Concept & Reasoning
Cross-linked polyethylene has high dielectric strength, low dielectric loss and good moisture/chemical resistance, while its cross-linked molecular structure permits higher operating temperature than thermoplastic polyethylene. PVC is common in lower-voltage applications but is not the preferred main insulation for modern HV cables.
How to Solve It in the Exam
Modern HV/EHV extruded cable insulation → XLPE.
Important Exam PointDo not confuse outer sheath/jacket material with primary high-voltage insulation.
Related Revision Path
This question sits in the revision path Power System → High Voltage Engineering → Power Cables .
