A hollow sphere of external radius R and thickness t (< < R) is made of a metal of density `rho`. The sphere will float in water if

Options

A. `t le R/rho`
B. `t le (R)/(3rho)`
C. `t le (R)/(2rho)`
D. `t ge (R)/(2 rho)`

Answer

B

Explanation

As law of flotation
`(4pi R^2 t)rho le 4/3 pi R^3 implies t le (R)/(3rho)`