Coaxial cable - capacitance, leakage current and power lost

[polibuda]

Homework Statement

Determine the capacity, leakage current and
power lost in the single-core segment
length coaxial cable
l = 1 km, operating with voltage
U = 5 kV.

Relevant Equations

γ = 5 10^(-9) S/m
r1 = 10 mm,
r2 = 27,3 mm
εr = 3,5

Could somebody check my solution?

 

[jbsteele]

Let $A \subseteq B$.To prove that the power set of $A$ is a subset of the power set of $B$, we need to prove that $\mathcal{P}(A) \subseteq \mathcal{P}(B)$.Let $X \in \mathcal{P}(A)$. This means that $X \subseteq A$. Since $A \subseteq B$, it follows that $X \subseteq B$. Therefore, $X \in \mathcal{P}(B)$.This proves that $\mathcal{P}(A) \subseteq \mathcal{P}(B)$.Yes, your solution is correct.