Question

3.The thin wire of 3cm radius float on the surface of the liquid.The pull required to raise the ring before the film breaks is 30.14x10power-3N more than its weight.The surface tension of the liquid (N/M) is

Answer 1

Dear Student,

$$\begin{gathered} \mathrm{F}=30.14\times {10}^{-3}\mathrm{N} \\ \mathrm{radius},\mathrm{r}=3\mathrm{cm}=3\times {10}^{-2}\mathrm{m} \\ \mathrm{surface}\mathrm{tension},\mathrm{T}=\frac{\mathrm{F}}{4\mathrm{\pi r}} \\ \mathrm{T}=\frac{30.14\times {10}^{-3}}{4\times 3.14\times 3\times {10}^{-2}}=7.99\times {10}^{-2}\mathrm{N}/\mathrm{m} \end{gathered}$$