# A solid sphere of radius r made of a material of bulk modulus K  is surrounded by a liquid in a cylindrical container. A massless piston of area a floats on the surface of the liquid. When a mass m is placed on the piston to compress the liquid, the fractional change in the radius of the sphere (dr/r) is a) /mg b) 3mg c) Mg/3 d) Mg/

## Question ID - 56275 | SaraNextGen Top Answer A solid sphere of radius r made of a material of bulk modulus K  is surrounded by a liquid in a cylindrical container. A massless piston of area a floats on the surface of the liquid. When a mass m is placed on the piston to compress the liquid, the fractional change in the radius of the sphere (dr/r) is a) /mg b) 3mg c) Mg/3 d) Mg/

Answer Key / Explanation : (c) -

(c)

In volume of sphere in liquid,

V =                                                …….(i)

When mass m is placed on the piston, the increased pressure   since this increased pressure is equally applicable to all directions on the sphere, so there will be decrease in volume of sphere, due to decrease in its radius. From Eq.(i), change in volume is

Now,