A block of silver of mass `4 kg` hanging from a string is immersed in a liquid of relative density `0.72`. If relative density of silver is `10`, then tension in the string will be

Options

A. 37.12 N
B. 42 N
C. 73 N
D. 21 N

Answer

A

Explanation

Let `rho_(S),rho_(L)` be the density of silver and liquid Also m and V be the mass and volume of silver block
`:.` Tension in string = mg - bouyant
force
`T = rho_(S) Vg - rho_(L) Vg = (rho_(S) - rho_(L))Vg`
Also `V = (m)/(rho s)`
`T = ((rho_(S)-rho_(s))/(rhos))mg`
`=((10-0.72)xx10^(3))/(10xx10^(8))xx4xx10=37.12 N`.