MCQ
A stone is hung in air from a wire which is stretched over a sonometer. The bridges of the sonometer are $L \,cm$ apart when the wire is in unison with a tuning fork of frequency $ N$. When the stone is completely immersed in water, the length between the bridges is $l \,cm$ for re-establishing unison, the specific gravity of the material of the stone is
- A$\frac{{{L^2}}}{{{L^2} + {l^2}}}$
- B$\frac{{{L^2} - {l^2}}}{{{L^2}}}$
- ✓$\frac{{{L^2}}}{{{L^2} - {l^2}}}$
- D$\frac{{{L^2} - {l^2}}}{{{L^2}}}$
