Q 11-13-020NEETJEE MainMedium
A mass on a spring oscillates with period $T$. The spring is cut into two equal halves and the same mass is attached to one half. The new period is
Answer: (B) $\dfrac{T}{\sqrt{2}}$
Concept. For a spring $kl$ is constant, so each half has $2k$; $T \propto \dfrac{1}{\sqrt k}$.
Step 1. New period. $T' = \dfrac{T}{\sqrt2}$.
Answer. $\dfrac{T}{\sqrt2}$ (Option B).
Solution by Sreeraj P, M.Sc Physics