A vessel filled with water is kept on a weighing pan and the scale adjusted of zero. A block of mass M and density `rho` is suspended by a masselss spring of spring constant k. This block is submerged inside into the water in the vessel. What is the reading of the scale /

Explanation

Refer

since scale pass is adjusted to zero without putting block in water, so the final reading on the scale when block is immersed in water will be equal to upthrust on the block due to water ` =V rho_w g = (M)/(rho) rho_wg`