Question 8 of 311
Two metal spheres of radius and have same surface charge density . If they are brought in contact and then separated, the surface charge density on smaller and bigger sphere becomes and , respectively. The ratio is.
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Answer: (D) 3
For conducting sphere,
After contact,
$\begin{aligned}
& \sigma_1 r_1=\sigma_2 r_2 \\
& \frac{\sigma_1}{\sigma_2}=\frac{r_2}{\mathrm{r}_1} \\
& \frac{\sigma_1}{\sigma_2}=3
\end{aligned}$
After contact,
$\begin{aligned}
& \sigma_1 r_1=\sigma_2 r_2 \\
& \frac{\sigma_1}{\sigma_2}=\frac{r_2}{\mathrm{r}_1} \\
& \frac{\sigma_1}{\sigma_2}=3
\end{aligned}$