An iron needle slowly placed on the surface of water floats because

Two pieces of glass plates placed one upon the other with a little water in between them cannot be separated easily because of:

If a drop of liquid breaks into smaller droplets,it results in the lowering of the temperature of the droplets. Let a drop of radius $R$ break into $N$ small droplets,each of radius $r$. Estimate the drop in temperature.

The property of surface tension is obtained in

$A$ soap film is formed on a circular frame. $A$ loop of thread is lying on the film. If the film inside the loop is broken,then the tension in the thread will be: ($R =$ radius of the loop,$T =$ surface tension of the liquid)

Arrange the following liquids in increasing order of surface tension: Water,Mercury,Soap solution.