Q: When a block of iron floats in mercury at 0°C, fraction k_{1} of its volume is submerged, while at the temperature 60°C, a fraction k_{2} is seen to be submerged. If the coefficient of volume expansion of iron is γ_{Fe} and that of mercury is γ_{Hg}, then the ratio k_{1}/k_{2} can be expressed as

(a) $\large \frac{1 + 60 \gamma_{Fe}}{1 + 60 \gamma_{Hg}} $

(b) $\large \frac{1 – 60 \gamma_{Fe}}{1 + 60 \gamma_{Hg}} $

(c) $\large \frac{1 + 60 \gamma_{Fe}}{1 – 60 \gamma_{Hg}} $

(d) $\large \frac{1 + 60 \gamma_{Hg}}{1 + 60 \gamma_{Fe}} $

Ans: (a)