A beaker containing water is placed on a scale balance which indicates a mass of 0.5 kg.A glass sphere of mass 0.2 kg is suspended from a string and immersed in water such that it doesn't touches the beaker. if the relative density of glass sphere is 2.5 then the reading of the balance will changes to



Relative density d = Dg /Dw = 2.5     (Dg = density of glass sphere  ,Dw = density ofwater)
mass of beaker is 0.5 Kg
mass of glass sphere is m = 0.2 kg
force on glass sphere when immersed in water are ; force of gravity downward mg in magnitude and due to water upward force V*Dw*g
V = volume of glass sphere = m/Dg
net force on glass sphere is = (m - m*Dw/Dg)*g downward
                                         = (0.2 - 0.2/2.5)*g
                                         = 0.12g downward
total reading of the balance is = (0.5 +0.12)Kg = 0.62Kg
hence reading of the balance will change to 0.12Kg