Two metal spheres of radius R and 3 R have same surface charge density σ. If they are brought in contact and then separated, the surface charge…

Two metal spheres of radius $\displaystyle R$ and $\displaystyle 3 R$ have same surface charge density $\displaystyle \sigma$. If they are brought in contact and then separated, the surface charge density on smaller and bigger sphere becomes $\displaystyle \sigma_1$ and $\displaystyle \sigma_2$, respectively. The ratio $\displaystyle \frac{\sigma_1}{\sigma_2}$ is