A machine mounted on a single coil spring has a period of free vibration of T. If the spring is cut into four equal parts and placed in parallel and the machine is mounted on them, then the period of free vibration of the new system will be
- A. 16 T
- B. T/4
- C. 4 T
- D. T/16
Answer: B. T/4
Explanation: Stiffness of cut spring $k' = 4k$. Four in parallel $k_{eq} = 4k' = 16k$. New period $T' \propto 1/\sqrt{k_{eq}} \propto 1/\sqrt{16} = 1/4$. So $T' = T/4$.