Question

If a spring of spring constant $k$ extends by $x$ on loading due to an applied force $F$, then the energy stored by the spring is

• A. $\frac{F^2}{2x}$
• B. $\frac{F^2}{2k}$
• C. $\frac{2x}{F^2}$
• D. $\frac{2F^2}{k}$

Answer 1

The correct option is B

$\frac{F^2}{2k}$

We have $F=kx$ and $U=\frac{k{x}^2}{2}$.

Therefore,

$U=\frac{F^2}{2k}$