Question

The expression 0.01E + 0.003E2 gives the thickness in millimeters (mm) of the insulation needed for a high voltage cable. E is the number of kilovolts carried by the cable. What thickness of insulation material is needed for 5 kilovolt cable?

Answer 1

Answer: 0.125mm... I don't know why the guy before me was rated so low I got the exact same answer.

Question: The expression 0.01E+0.003E^2 gives the thickness in millimeters (mm) of the insulation needed for a high-voltage cable. E is the number of kilovolts carried by the cable.what thickness of insulation material is needed for a 5 kilovolt cable?

Answer 2

The thickness is given by
t = 0.01E + 0.003E² mm
where
E = kilovolts

For a 5 kilovolt cable, set E to 5  to obtain
t = 0.01*5 + 0.003*5²
  = 0.05 + 0.075
  = 0.125 

Answer: 0.125 mm