Q: A hollow metal sphere is found to float in water with the highest point just touching the free surface of water. If ‘d’ is the density of the metal in cgs units, the fraction that represents the volume of the hollow in terms of the volume of the sphere is

(a) $ \displaystyle \frac{1}{d}$

(b) $ \displaystyle (1-\frac{1}{d}) $

(c) $ \displaystyle \frac{d}{d-1}$

(d) $ \displaystyle (1+\frac{1}{d}) $

Ans: (b)