MCQ
In an experiment with sonometer when a mass of $180\,g$ is attached to the string, it vibrates with fundamental frequency of $30\,Hz$. When a mass $m$ is attached, the string vibrates with fundamental frequency of $50\,Hz$. The value of $m$ is $.........\,g$.
- A$400$
- ✓$500$
- C$300$
- D$200$
