<p>A liquid column of height 0.04cm&nbsp; balances excess pressure of a soap bubble of certain radius. If density of liquid is&nbsp;&nbsp;<span class="equation">\(8\times10^3kgm^{-3}\)</span>&nbsp;&nbsp;and surface tension of soap solution is&nbsp;<span class="equation">\(0.28Nm^{-1}\)</span>, then diameter of the soap bubble is __________cm . (if g = 10&nbsp;<span class="equation">\(10ms^{-2}\)</span>)&nbsp; &nbsp;&nbsp;</p>