A cylindrical body of cross-sectional area A, height H and density $\rho_s$, is immersed to a depth h in a liquid of density $\rho$, and tied to the bottom with a string. The tension in the string is
- A. $\rho ghA$
- B. $(\rho h - \rho_s H)gA$
- C. $(\rho - \rho_s)ghA$
- D. $(\rho_s - \rho)ghA$
Answer: B. $(\rho h - \rho_s H)gA$
Explanation: Forces: Tension T (down) + Weight W (down) = Buoyancy B (up). $T = B - W = (\rho g A h) - (\rho_s g A H) = gA(\rho h - \rho_s H)$.