Question

Electric Fields 1. In downtown, underground cables are used to distribute electrical powers to the end users. A cable has the inner diameter of 5 cm. and outer diameter has an optimum dimension. The insulator has 2 layers. The outer layer is 2 times thicker than the inner layer.

Outer layer εr2 = 2 tgδ₂ = 2% rho₂ = 4x10¹² Ω-cm
Inner layer εr1 = 4 tgδ₁ = 4% rho₁ = 2x10¹² Ω-cm

Calculate the breakdown voltage.

Answer 1

To calculate the breakdown voltage of the cable, use the formula V = (1 / (2 * π * ε₀)) * (Q / ln(R₂/R₁)), where V is the breakdown voltage, ε₀ is the vacuum permittivity, Q is the charge per unit length, and R₁ and R₂ are the inner and outer radii of the cable.

Step-by-step explanation:

The breakdown voltage of the cable can be calculated using the formula:

V = (1 / (2 * π * ε₀)) * (Q / ln(R₂/R₁))

Where V is the breakdown voltage, ε₀ is the vacuum permittivity, Q is the charge per unit length, and R₁ and R₂ are the inner and outer radii of the cable respectively.

Using the given values, we can calculate the breakdown voltage.