On heating water, bubbles being formed at the bottom of the vessel detach and rise. Take the bubbles to be spheres of radius R and making a circular contact of radius r with the bottom of the vessel. If r < < R, and the surface tension of water is T, value of r just before bubbles detach is : (density of water is $\rho_w$) <br>

Question

( A ) $r = R^2 \sqrt{\frac{2 \rho_w g}{3T}}$
( B ) $r = R^2 \sqrt{\frac{ \rho_w g}{3T}}$
( C ) $r = R^2 \sqrt{\frac{3 \rho_w g}{T}}$
( D ) $r = R^2 \sqrt{\frac{ \rho_w g}{6T}}$