Electrical Field Lines "In Tension" I had a thought the other day about how I've read multiple places that one way to field of Electric field lines as "tense ropes" or "in tension", and was wondering if this would be an inward or outward tension? I suppose an inward tension would lend it self to the force of attraction between opposite charges, but it seems harder to picture for just a single point charge.
 
Bonus question: How does this "tense" rope analogy lend itself to the force of repulsion in like charges? Cheers!
Edit: Not sure why this was considered “off- topic” I got this notion from an MIT Lecture Here it is for reference

 A: The property that field lines repel each other can also be useful as is the property that lines can be between charges or a charge and infinity.
The repulsion property can be used for your third arrangement but you can also use the tension idea between a charge and infinity.
A single point charge which is not moving has no net tension force on it from the arrangement of symmetrically positioned field lines.
A: You can't interpret field lines as structural elements, since structural elements have internal actions that comes from a stress state: when you cut a structural element, you get actions on one side that are opposite w.r.t. to the actions on the other side, since internal internal actions depends on the normal vector of the surface considered. As an example:

*

*you can think at a structural element in tension if you cut a little element and find the internal actions of the two faces are opposite and pointing outwards, stretching the element;

*you can't think at a line field as an element in tension or compression: when you cut a small section of field line, you find the electric field pointing in the same direction at both extremes.

Remember the operative definition of the electric field, i.e. the force per unit charge that a test charge would experience when in that point of space.
Once, we understood this, we can say that both electric field and "elastic" field due to a linear spring are central fields, but with different trends as functions of the distance:

*

*electric field (as the gravitational field) goes as $\frac{1}{r^2}$


*elastic fields due to linear springs with constant stiffness goes as $r$.
In order to find an analogy with an elastic spring, you need a material whose elastic constant goes as $k \sim \frac{1}{r^3}$, so that the force goes as $\frac{1}{r^2}$
