Question

When spring is compressed its potential energy
A. Remains constant
B. Reduces
C. Increases
D. Nothing can be said about it.

Answer 1

Hint: In order to solve this question, we should know about Potential energy in physics. Potential energy is the energy of a body due to its position. Here we will discuss the potential energy of a spring in brief and then will figure out what happens to the potential energy of the spring when it is compressed.

Complete answer:
Every spring has a spring constant which is governed according to the hooke's law which states that, when we applied the force on a spring then it has the tendency to bring it back in its original position with a force known as retarding force and its given as $F = - kx$ where $x$ is the distance to which spring is either compressed or stretched and K is called spring constant.

This tendency of spring to bring it back in original position is due to stored potential energy in the spring which is related as $P.E = \dfrac{1}{2}k{x^2}$ and hence we see that, potential energy is directly proportional to square of the distance to which spring is moved. Now, when the spring is compressed from its initial state the value of x increases and thus potential energy will also increase.

Hence, the correct option is C.

Note: It should be remembered that, as $P.E \propto {x^2}$ no matter if the spring is stretched or compressed the value of x will always increases from its original value so, the potential energy will always increase in case of compression as well as stretching the spring.