A spring whose unstrentches length is $l$ has a force constant $k.$ The spring is cut into two pieces of unstretches lengths $l_1$ and $l_2$ where, $l_1=n{l}_2$ and $n$ is an integer. The ratio $k_1/k_2$ of the corresponding force constants, $k_1$ and $k_2$ will be:

• A

  $\frac{1}{n^2}$
• B

  $n^2$
• C

  $n$
• Correct answer
  D

  $\frac{1}{n}$

Hence, the correct answer is option: 'D'.