capacity of a close bounded interval in the plane

Question

I am new to the topic of capacities and I am working in questions, like what is the capacity of a line segment?. In Some properties of capacity there is a really nice answer to the question posted there, my question is under the same argument given in this answer can I claim that $\text{cap}_{p}([a,b])=0$?. Here I am thinking that $[a,b]$ is a bounded closed interval in $\mathbb{R}$