A hollow spherical shell at outer radius floats just submerged under the water surface

PHYSICS · Single correct · CBSE · Physics · Gravitation · Gravitation

Problem

A hollow spherical shell at outer radius

R

floats just submerged under the water surface. The inner radius of the shell is

r

. If the specific gravity of the shell material is

\frac{27}{8}

w.r.t water, the value of

r

is: (1)

\frac{8}{9}R

(2)

\frac{4}{9}R

(3)

\frac{2}{3}R

(4)

\frac{1}{3}R