Question

A silver ingot weighing $2.2kg$ is held by a string so as to be completely immersed in a liquid of relative density $0.8$. The relative density of silver is $10.5$. The tension in the string in $kg-wt$ is-

• A. $1.6$
• B. $1.94$
• C. $31$
• D. $5.25$

Answer 1

The correct option is B $1.94$

Mass of ingot $=2.2Kg$

Relative density of silver $=10.5$

Volume of silver = $\frac{2.2}{10.5}{m}^3$

Relative density of fluid in which the ingot is immersed $=0.8$

Upward buoyant force on the ingot= $\frac{2.2}{10.5}\times 0.8\times 9.8$

g=$9.8m/s^2$

Net tension in the string = $2.2\times 9.8-\frac{2.2}{10.5}\times 0.8\times 9.8=19.89N=2.03kg-wt$

Option B is closest.