Question

Potential Energy is an example of Non-conservative force?
A. True
B. False

Answer 1

Hint: Non-Conservative force means work done by that force on an object is dependent on the path, whether the path is straight line or circular.
Potential Energy is the energy stored in an object when it is subject to move in the direction opposite to conservative force (or simply work done against conservative force).

Complete step by step solution:
As we know that work done means Force multiplied by displacement in the direction of applied force, $W=F.s$, and non-conservative force is path dependent. But potential energy is path independent of path and depends only upon initial and final position. So, if you move an object against the direction of conservative force, it will store energy in the form of potential energy.

If you lift an object vertically straight to a certain height and again put it back to its original position, then, work done by gravitational force on the object is Zero, because displacement of the object is negative, as displacement is against gravity, when you are lifting it, and positive , as displacement is towards gravity ,when you are putting it back .
It is clearly indicating that Gravitational force is conservative in nature.
But if you move an object on a horizontal rough surface from point A to point B and again move it from point B to point A, then work done by frictional force on the object is not Zero because W =F. s, where F is Frictional force and s is displacement of object .
Let displacement of objects, from A to B be s.
$W_1=F\times \left(-s\right)$, because displacement is opposite to the frictional force.
Now, from point B to A.
$W_2=F.s$ , again displacement is opposite to the frictional force.
Total Work done by frictional force is $W_1+W_2$,
Hence Total work done = $-2\times F\times s$,
It clearly indicates that frictional force is non-conservative force.

Now suppose you lift an object from ground vertically to a certain height, thus the work done on that object by you, is against gravitational force (which is conservative force), Hence, potential energy of that object increases. Path will be linear or zig-zag, it doesn’t affect the potential energy of the object.
But if you move an object on the horizontal rough surface, thus the work done on that object by you, is against Frictional force (which is non-conservative), hence, potential energy remains unaffected.
So, it is clear that the potential energy depends on initial and final position, but not on path, whether it is linear or circular, work done is the same on both of the paths.
Non-conservative force depends upon the chosen path, if the path is linear, then the work done is different from the work done on the circular path.

Hence, Potential Energy is not an example of Non-conservative energy.
$\therefore$ Option (b) is correct.

Note: Work done by Non-conservative force is dependent on path.
Potential energy doesn’t depend upon path, but only on initial and final position.