1) Assume that a drop of liquid evaporates by decrease in its surface energy so that its temperature remains unchanged. What should be the minimum radius of the drop for this to be possible? The surface tension is T, the density of liquid is $\rho$ and L is its talent heat of vaporization A) $\rho$ L/T B) $\sqrt{T/\rho L}$ C) T/ $\rho$ L D) 2T/ $\rho$ L Answer: Option DExplanation:Decrease in surface energy= hear required in vaporization $\therefore$ $ T(ds)= L(dm)$ $\therefore$ $ T(2)(4\pi r)dr= L(4\pi r^{2}dr)\rho$ $\therefore $ $ r= \frac{2T}{\rho L}$
