Q116 / 120 · JEE Main 2007 · Physics
Two springs, of force constants $k_1$ and $k_2$, are connected to a mass $\mathrm{m}$ as shown. The frequency of oscillation of the mass is $\mathrm{f}$. If both $k_1$ and $k_2$ are made four times their original values, the frequency of oscillation becomes


- A$\mathrm{f / 2}$
- B$\mathrm{f / 4}$
- C$4 \mathrm{f}$
- Correct answerD$2 \mathrm{f}$
Solution
$\begin{aligned} f & =\frac{1}{2 \pi} \sqrt{\frac{k_1+k_2}{m}} \\ f^{\prime} & =\frac{1}{2 \pi} 2 \sqrt{\frac{k_1+k_2}{m}}=2 f\end{aligned}$
Hence, the correct answer is option: 'D'.