• # question_answer A spring whose unstretched length is $l$ has a force constant k. The spring is cut into two pieces of un stretched 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 : [JEE Main 12-4-2019 Afternoon] A) $\frac{1}{{{n}^{2}}}$ B) ${{n}^{2}}$ C) $\frac{1}{n}$ D) $n$

 [c]${{k}_{1}}=\frac{C}{{{\ell }_{1}}}$ ${{k}_{2}}=\frac{C}{{{\ell }_{2}}}$ $\frac{{{k}_{1}}}{{{k}_{2}}}=\frac{C{{\ell }_{2}}}{{{\ell }_{1}}C}{{\ell }_{2}}=\frac{{{\ell }_{2}}}{n{{\ell }_{2}}}=\frac{1}{n}$