Correct Answer - Option 3 : Voltage grading of cables
Concept of Voltage Rating:
The voltage rating of a cable refers to the maximum voltage to which it may be connected and have running through it.
- Voltage rating specifies the safe voltage that the insulation of a cable can withstand.
Voltage Rating of cable gives the capacity of insulation for that cable withstand. Voltage grading is nothing but the voltage rating for which insulation of cable can withstand. so the answer is voltage grading of cable specifies the safe voltage that the insulation of a cable can withstand.