Two planets have the same average density

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Two planets have the same average density but their radii are ${R_1}$ and ${R_2}$. If acceleration due to gravity on these planets be ${g_1}$ and ${g_2}$ respectively, then

A

$\frac{{{g_1}}}{{{g_2}}} = \frac{{{R_1}}}{{{R_2}}}$

B

$\frac{{{g_1}}}{{{g_2}}} = \frac{{{R_2}}}{{{R_1}}}$

C

$\frac{{{g_1}}}{{{g_2}}} = \frac{{R_1^2}}{{R_2^2}}$

D

$\frac{{{g_1}}}{{{g_2}}} = \frac{{R_1^3}}{{R_2^3}}$

Two planets have the same average density but their radii are ${R_1}$ and ${R_2}$. If acceleration due to gravity on these planets be ${g_1}$ and ${g_2}$ respectively, then

$g = \frac{4}{3}\pi \rho GR$. If $\rho $ = constant then $\frac{{{g_1}}}{{{g_2}}} = \frac{{{R_1}}}{{{R_2}}}$