I WANT FULL CLARITY ABOUT TENSION AND POTENTIAL ENERGY?HOW THESE WILL APPEARS ?

tension is the pulling force exerted by a string, cable, chain, or similar solid object on another object. It results from the net electrostatic attraction between the particles in a solid when it is deformed so that the particles are further apart from each other than when at equilibrium, where this force is balanced by repulsion due to 
electron cells; as such, it is the pull exerted by a solid trying to restore its original, more compressed shape. Tension is the opposite of 
compression. Slackening is the reduction of tension.

As tension is the magnitude of a force, it is measured in newtons and is always measured parallel to the string on which it applies. There are two basic possibilities for systems of objects held by strings:Either acceleration is zero and the system is therefore in equilibrium, or there is acceleration and therefore a net force is present. Note that a string is assumed to have negligible mass.

Potential Energy:-

An object can store energy as the result of its position. For example, the heavy ball of a demolition machine is storing energy when it is held at an elevated position. This stored energy of position is referred to as potential energy. Similarly, a drawn bow is able to store energy as the result of its position. When assuming its 

usual position (i.e., when not drawn), there is no energy stored in the bow. Yet when its position is altered from its usual equilibrium position, the bow is able to store energy by virtue of its position. This stored energy of position is referred to as potential energy.