The ratio of frequencies of two oscillating pendulums are $3: 2$. Their lengths are in the ratio

The ratio of frequencies of two oscillating pendulums are $3: 2$. Their lengths are in the ratio
  1. $\sqrt{2}: \sqrt{3}$
  2. $9: 4$
  3. $\sqrt{3}: \sqrt{2}$
  4. $4: 9$

Solution

The frequency of oscillation is given by: $\mathrm{n}=\frac{1}{2 \pi} \sqrt{\frac{\mathrm{g}}{\mathrm{L}}}$ So, Frequency $\mathrm{n} \propto \frac{1}{\sqrt{\mathrm{L}}}$ $\Rightarrow \frac{\mathrm{n}_1}{\mathrm{n}_2}=\sqrt{\frac{\mathrm{L}_2}{\mathrm{~L}_1}}$ $\Rightarrow \frac{\mathrm{L}_1}{\mathrm{~L}_2}=\frac{\mathrm{n}_2^2}{\mathrm{n}_1^2}=\frac{4}{9}$

Asked in: MHT CET 2022 (05 Aug Shift 2)

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