Questions in Mechanical Properties of Fluids

Select	Question
	Which of the following statements are true in case when two water drops coalesce and make a bigger drop
	8000 identical water drops are combined to form a big drop. Then the ratio of the final surface energy to the initial surface energy of all the drops together is
	The surface energy of liquid film on a ring of area $0.15\ {{m}^{2}}$ is (Surface tension of liquid $=5N{{m}^{-1}})$
	8 mercury drops coalesce to form one mercury drop, the energy changes by a factor of
	If work done in increasing the size of a soap film from $10\ cm\times 6\ cm$ to $10\ cm\times 11\ cm$ is $2\times {{10}^{-4}}J,$ then the surface tension is
	A mercury drop of radius $1cm$ is sprayed into ${{10}^{6}}$drops of equal size. The energy expended in joules is (surface tension of Mercury is $460\times {{10}^{-3}}N/m)$
	When two small bubbles join to form a bigger one, energy is
	A film of water is formed between two straight parallel wires of length 10cm each separated by 0.5 cm. If their separation is increased by 1 mm while still maintaining their parallelism, how much work will have to be done (Surface tension of water =$7.2\times {{10}^{-2}}N/m)$
	A drop of mercury of radius $2$ mm is split into $8$ identical droplets. Find the increase in surface energy. (Surface tension of mercury is $0.465\ J/{{m}^{2}}$)
	Two small drops of mercury, each of radius $R$, coalesce to form a single large drop. The ratio of the total surface energies before and after the change is